The 4 Modern States of Matter Matter can take four states:

Solid○ Solid is the state in which matter

maintains a fixed volume and shape.

Liquid○ liquid is the state in which matter

maintains a fixed volume but adapts to the shape of its container

Gas○ Gas is the state in which matter

expands to occupy whatever volume is available.

Plasma○ Plasma can be considered highly

ionized particles that have distinct properties, so that it is usually considered as a different phase or state of matter

Animation

Another animationDefinitions from wikipedia

The states of matter and their properties can be

defined and explained by the motion of particles,

(atoms and molecules). The explanation is called Kinetic

Molecular Theory.

Tutorial

http://scienceprojectideasforkids.com/2009/states-of-matterenthalpy/ by J VanCleave

Changing States of Matter

• Name the four states of matter?• What states of matter are fluid,

can flow?• Which state of matter has the

strongest bonds between particles?• Which states of matter have no

bonds between particles?• Which state of matter is the most

energetic?•Which state of matter has the least

amount of heat?• What is enthalpy?

• How are temperature, energy and state of matter related?

• Define: sublimation, deposition, melting, freezing, evaporation,

condensation, ionization, deionization.

The three states of matter that are most often studied are gas, liquid, and solid. A fourth state of matter, plasma, which is much hotter (more energetic) than gas is included here.

Notice that plasma can only be formed from a gas which is ionized (changed into charged particles).

To make a change from one state of matter requires a change in energy.

For example, the change form the liquid state to a gas is called vaporization.

The amount of energy (heat) needed to make this change is called the enthalpy (heat) of vaporization.

Since the gas state of matter is hotter than is the liquid state, enthalpy of vaporization is the amount of heat that must be added to the liquid for it to change into a gas.

Phase Change Animation

MovieSlide by: J. Levasseur ©

Assumptions of Kinetic Molecular Theory1. Gases are composed of a large number of particles that

behave like hard, spherical objects in a state of constant, random motion.

2. These particles move in a straight line until they collide with another particle or the walls of the container.

3. These particles are much smaller than the distance between particles. Most of the volume of a gas is therefore empty space.

4. There is no force of attraction between gas particles or between the particles and the walls of the container.

5. Collisions between gas particles or collisions with the walls of the container are perfectly elastic. None of the energy of a gas particle is lost when it collides with another particle or with the walls of the container.

6. The average kinetic energy of a collection of gas particles depends on the temperature of the gas and nothing else.

Kinetic Molecular Theory

• The Kinetic-Molecular Theory ("the theory of moving molecules)

• The Kinetic Molecular Theory is based on the idea that particles of matter are always in motion.

• Kinetic-molecular theory can be used to explain the properties of solids, liquids and gases in terms of the energy particles and the forces that act between them.

Solid Liquid Gas

TutorialAnimation

• What is kinetic Molecular Theory?

• How does Kinetic Molecular theory

explain the behavior of gases?

• What is the relationship between a

gases’ volume, pressure an

temperature?• Why is more energy required to turn liquid water into a gas than other molecules (H2S

for example)?

Springfield Central High SchoolChemistry

John Levasseurlevasseurj@sps.springfield.ma.uscentralscience.net

SECTION 2: THE ATOM

Atomic Structure and Nuclear Chemistry

Slide by: J. Levasseur ©

Video Part 1 on Atoms

Video Part 2 on Atoms

MA State Frameworks

2. Atomic Structure and Nuclear Chemistry• Central Concepts:

– Atomic models are used to explain atoms and help us understand the interaction of elements and compounds observed on a macroscopic scale.

– Nuclear chemistry deals with radioactivity, nuclear processes, and nuclear properties. – Nuclear reactions produce tremendous amounts of energy and lead to the formation of

elements. • 2.1 Recognize discoveries from Dalton (atomic theory), Thomson (the electron), Rutherford

(the nucleus), and Bohr (planetary model of atom), and understand how each discovery leads to modern theory.

• 2.2 Describe Rutherford’s “gold foil” experiment that led to the discovery of the nuclear atom. Identify the major components (protons, neutrons, and electrons) of the nuclear atom and explain how they interact.

• 2.3 Interpret and apply the laws of conservation of mass, constant composition (definite proportions), and multiple proportions.

• 2.4 Write the electron configurations for the first twenty elements of the periodic table.• 2.5 Identify the three main types of radioactive decay (alpha, beta, and gamma) and

compare their properties (composition, mass, charge, and penetrating power).• 2.6 Describe the process of radioactive decay by using nuclear equations, and explain the

concept of half-life for an isotope (for example, C-14 is a powerful tool in determining the age of objects).

• 2.7 Compare and contrast nuclear fission and nuclear fusion.Slide by: J. Levasseur ©

The Atom • The Basic Model of an Atom – Atoms- tiny units of mass that take up space; these

units determine the properties of matter. These tiny units have no net charge having equal positive protons and negative electrons.

– The atom consists of two regions.1. The nucleus

• Protons• Neutrons

2. Energy levels (electron clouds)• Electrons• Specific amounts of energy

TutorialAnimationSlide by: J. Levasseur ©

• Protons are positively charged subatomic particles found in the nucleus– The number of protons in an atom will

determine what type of element.– The atomic number of an element is the

number of protons in that element’s atoms’ nuclei

• Neutrons are particles with no net charge and found in the nucleus

The Atom’s Nucleus Protons are positively

charged subatomic particles found in the nucleus

Neutrons have no net charge and allow the positively charged protons to be tightly packed into the nucleus

Animation

Slide by: J. Levasseur ©

• What are atoms?• What are protons, neutrons

and electrons?• What is he nucleus of an

atom?• What makes one kind of atom, (element) different

from another?• What is the “Strong Force,

and why is the Strong Force an example of E=mc2?

• Electrons are negatively charged subatomic particle found in discrete energy levels around the atom’s nucleus .– Electrons are found in the outer

regions surrounding the nucleus called energy levels also known as energy shells.

• The outermost energy level is called the valence level. – The electrons found in the

valence level is called the valence electron.

– The number of valence electrons determine the chemical reactions of the element.

– How an atom behaves when it encounters other atoms is determined by valence electrons.

The Atom’s Electrons (e-)

• What are electrons?• What is the valence level in an

atom?• How do electrons determine the behavior of groups of the periodic

table? • How many valence electrons

does each of the following atoms have: Na, B, Si, Sb, Br, Kr, K, C, He

Slide by: J. Levasseur ©

• The Mole– The mole is the SI unit for amount of

substance.– A mole (abbreviated mol) is the

amount of a substance that contains as many particles as there are atoms in exactly 12 g of carbon-12.

– There are 6.022 1415 × 1023 atoms in exactly 12 g of carbon-12.

– There are approximately 6.02 x 1023 carbon atoms in 12 grams of carbon

• So a Mole is 6.02 x 1023 particles, (atoms, molecules, formula units, protons, ect)

• Avogadro’s Number• Avogadro’s number is the number of

particles in exactly one mole of a pure substance.

• 6.022 1415 × 1023

What is a Mole? Animation

Animation

• The Mole is a counting word with a value of about 6.02 x 1023

• Think of other counting words in English– Pair = 2– Dozen = 12– Gross = 144– Grand = 1000– Mole = 6.02 x 1023

• 6.02 x 1023 (mole) is such an important number it was given a name, Avogadro’s Number– Avogadro was a famous Italian

chemist– So, 6.02 x 1023 is often referred

to as Avogadro’s Number.• Like 3.14 is often referred to

as Pi

Knowing the mole value for chemicals is the key to understanding so many other values that you can measure for in a lab.

What is a Mole?• The Mole

– The mole is the SI unit for amount of substance.

–A mole (abbreviated mol) is the amount of a substance that contains as many particles as there are atoms in exactly 12 g of carbon-12.

• Avogadro’s Number– Avogadro’s number is the number of

particles in exactly one mole of a pure substance.

– 6.022 1415 × 1023

Central Concepts

Slide by: J. Levasseur ©

Atomic Mass & Molar Mass• Atomic Mass

– When you look at a Periodic Table, the numbers under the element symbols are the relative atomic weights.

• For example, notice helium and neon, it shows that neon is basically 5 times heavier (20.1797/4.00260). If we compare helium to carbon, we see that carbon is about 3 times heavier (12.0107/4.00260)

– These are relative weights, but if we count out a mole of these atoms, then these numbers is the weight in grams . In other words, a mole of sulfur weighs 32.066 grams

• Molar Mass– The mass of one mole of a pure substance is

called the molar mass of that substance.– Molar mass is usually written in units of

g/mol.– The molar mass of an element is numerically

equal to the atomic mass of the element in atomic mass units.

Tutorial

Solving a Grams per Mole Problem with the This per that triangle

If you have 880 grams of Calcium (Ca), how many moles of Calcium do you have? What is the “This”? What is the “That”? What is the “This per That”?

How do you find the molar mass of Ca?

This

This per That That

880 grams

40 g/mol ? 22

mol

.

We know the “This” is 880 grams We can look up Calcium on the periodic table and find out

the molar mass is 40 g/mol So we can solve for the number of moles.

mol

Solving a Grams per Mole Problem with the This per that triangle

If you have 883.5 grams of Cobalt (Co), how many moles of Cobalt do you have? What is the “This”? What is the “That”? What is the “This per That”?

How do you find the molar mass of Co?

This

This per That That

883.5 grams

58.9 g/mol ? 15 mol

.

We know the “This” is 883.5 grams We can look up the molar mass of Co and find out the it is

58.9 g/mol So we can solve for the number of moles.

How many moles of cobalt (Co) are in 353.4 grams of cobalt?How many moles of Indium (In) are in 430.5 grams of In?

What is the mass of 10 moles of cobalt ?What is the mass of 7.5 moles of Indium? Slide by: J. Levasseur ©

Next Problem: Grams per mole• You have a sample of .66 moles of Potassium (K), how much should your

sample weigh?• What is the “This” in our Problem?• What is the “That” in our Problem?• What is the “This per That”?

This

This per

ThatThat

.

What is the mass of 2.5 moles of Na?

How many moles of carbon are there in 66

grams of carbon?What is the mass of

3 moles of oxygen, (careful HONClBrIF)?

5.3

• Democritus 400 B.C.– Nothing exists but atoms and empty space, everything

else is opinion– Atoms Indivisible geometric shapes

• Dalton 1830– Daltons Atomic Theory – Ball and Hook Model

• Thompson 1906– Discovery of subatomic particles: electron and protons– Plum Pudding Model from Thompson

• Rutherford 1909– Electrons orbiting the nucleus like planets around a

star– Discovery of atomic nucleus– Dense positive nucleus surrounded by negative

electron Rutherford– Did not obey laws of physics

• Bohr 1913– Electron movement by quantum rather than classical

physics– Electrons have discrete energy levels– Only works for hydrogen

• Modern Quantum (or orbital) Model 1924– Schrödinger and Heisenberg– Electron can not be located– Estimated location of electron based on probabilities

Democritus Dalton Thompson

Rutherford Bohr Schrödinger/ Heisenberg

1909

History of the Atomic Theory

Slide by: J. Levasseur ©

History of the Atomic Theory: Dalton• John Dalton’s recognition of atoms

and his Atomic Theory are an explanation of three Laws in Chemistry– 1. The Law of Conservation of Mass– 2. The Law of Definite Proportions – 3. The Law of Multiple Proportions

Dalton’s Atomic Theory can be summarized in 5 points:1. All matter is made of atoms2. Atoms are neither created nor destroyed3. Atoms of the same element are identical4. Atoms of different elements differ in mass,

shape, size and properties5. Chemical reactions involve the rearrangement

in the combinations of atoms in substances

Since the time of Dalton new discoveries have shown that Dalton was not completely correct; however his atomic theory is the foundation of our modern understanding of atoms.

•Dalton’s Atomic Model pictured atoms as balls and hooks that can grasp onto or release one

another• What are the 5 points of

Dalton's Atomic Theory?

Discovery of the Law of Conservation of Mass• Antoine-Laurent de Lavoisier was a Paris tax

collector who had a passion for scientific discovery. – Lavoisier was appointed to the King’s Academy for

science.– Lavoisier and his wife Marie worked together .– The Lavoisiers’ great discovery was based on the

fact that rusting iron gains mass rather than losses mass.

• Lavoisier showed that when water is passed through a heated rifle barrel some of the water disappears; however, the mass of the lost water can be accounted for by the increased mass of the rifle barrel and the mass of a new gas that appears, (hydrogen).

• Lavoisier stated that no mass is lost or gained in chemical reactions, the Law of Conservation of Mass.

Lavoisier’s conclusion was that mass is

neither gained nor lost in a chemical

reaction.This is known as the Law of Conservation

of Mass.

5.1

The Law of Conservation of Mass

• The Law of Conservation of Mass• States that mass is neither created nor

destroyed in any ordinary chemical reaction.

• Or more simply, the mass of substances produced (products) by a chemical reaction is always equal to the mass of the reacting substances (reactants).

• The law of conservation of mass: – Lavoisier: No mass is gained or lost in a

chemical reaction– After Dalton: Atoms are neither created,

nor destroyed, during any chemical reaction

Example:– 4g Hydrogen 32g oxygen 36g water

(H2O)– 1.00g carbon + 5.34g sulfur 6.34g

carbon disulphide – 2.00g carbon + 10.68g sulfur 12.68g

carbon disulphide

The Law of Conservation of Mass says that no matter is created or destroyed in chemical reaction.

From this we know that:1. All chemical equations MUST

have the same number of atoms of the different reactant

elements as atoms in the products.

2. The mass of the reactants MUST equal the mass of the

products.This law is the basis of balancing

chemical equations.

http://www.mi.mun.ca/users/edurnfor/1100/atomic structure/

5.1

Discovery of Electron&

Thomson Atomic Model

http://science.jrank.org/pages/620/Atomic-Models-Discovery-electron.html

AnimationJ.J. Thomson used what tool to discover what

part of the atom?

Animation 2

• The discovery of the first subatomic particle, the electron, came from experiments on the effects of electricity in a cathode ray tube done by J.J. Thomson.

• A cathode ray tube is a glass tube containing a gas. • When a paddle wheel was placed in a cathode ray

tube, the wheel spun and rolled from cathode to anode Thomson hypothesized that a stream of particles with mass were originating at the cathode and moving toward the anode caused the glow.

• When exposed to a magnetic field, the cathode ray was deflected in the same manner as an electric current, which has a negative charge.

• Thomson based his plum pudding model of the atom on these findings.

Know Rutherford’s experiment

E. Rutherford and the Gold Foil Experiment• Ernest Rutherford discovered that atoms

have a solid nucleus in 1909– Rutherford shot alpha particles at gold foil and

discovered some alpha particles bounced back• He concluded that the alpha particles were hitting a

solid nucleus

• Rutherford postulated a new atomic model– A model he knew was not correct since it

violated basic laws of physics.• A new explanation of motion had to made to

explain what was happening inside atoms. – The new explanation is called quantum mechanics

•Rutherford’s new atomic model had the negatively charged electrons indefinitely orbiting the positively charged nucleus.

•According to the classical laws of physics the electrons should fall into the nucleus.

Note: In the gold foil experiment

Rutherford showed that the nucleus is a small, dense and positively charged mass in the center

of the atom.

Animation

Movie

Slide by: J. Levasseur ©

History of the Atomic Theory: Bohr Model

• Niels Bohr concluded in 1913 that electrons inside atoms are “quantized”– Quantized means that the electrons have discrete

fixed energy levels.• This differed from Rutherford because Rutherford

did not see how an orbiting negative electron would not fall into a positive nucleus based on Newton's Laws.

• Bohr applied Max Planck’s idea that energy moves in tiny but discrete bundles at a time

– One bundle is a quanta

• Bohr initially recognized 6 energy levels but as measuring instruments improved 4 energy levels were agreed on, the outer three having sublevels.

– Like Rutherford’s, Bohr’s atomic model resembled the planets’ orbit around the sun.

• However, Bohr’s rings around the nucleus show levels of energy not pathways of the electrons.

The Bohr Atomic Model has four energy levels where

electrons travel about the nucleus only in these energy

levels or their sublevels; however, the model does

not state locations of where electrons are rather the model shows electron

energy levels.

Animation

Color, Light and Energy• Gas put in tubes then electrified

glows with beautiful colors.• What is happening?

– The electricity is exciting the electrons in the atoms of the gas.

– The electrons absorb a certain amount of energy then jump to higher energy levels; this is a quantum leap.

– The electrons are most stable in a lower state closer to the nucleus, so the electron will give off the same amount of energy that they absorbed then drop back to a ground state.

– The different elements will glow different colors because the different elements have different electron configuration.

• Each electron configuration means a different amount of energy will be absorbed then released as a light photon

• Different colors actually represent different amounts of energy

– Each gas will glow a different color since the different elements have differing electron configurations.

The Bohr Model Explains Line Spectra

• The energy levels and the sublevels correspond to the energy represented in the line spectra

• The Bohr model explains the phenomenon of line spectra rather than continuous color because the difference in energy between the energy levels determines color of light emitted when an electron moves from one energy level to another.

You GOT to see this periodic Table animated with the spdf levels again and showing the line spectra for various elements AGAIN

Energy and Orbitals of Bohr Model

Animation

How are the electrons moving around the nucleus?• Nobody really knows.

– In fact, it's more than that - current theory says that it is impossible to know.

• If you have planets in orbit around the sun, it is possible to plot out an orbit for them in mathematical terms.

• You can't predict locations of electrons. – To plot an orbit, you need to know, amongst other things,

exactly where the electron is, what direction it is heading in, and how fast it is going.

• The Heisenberg Uncertainty Principle says you can't know with certainty both where an electron is and where it is going next.

• If we can't know these essential facts, then we have no idea what the electrons are actually doing in the atom. All we can know about them is:– Their energy – Where they most likely are.

• Any particular electron will be found in a region of space known as an orbital.

– Each individual orbital can hold 2 electronshttp://www.chemguide.co.uk/atoms/properties/atomorbs.html Slide by: J. Levasseur ©

http://en.wikipedia.org/wiki/Atomic_orbital

AnimationElectron Orbitals and the Periodic Table• An atomic orbital is a

mathematical function that describes the wave-like behavior of electrons in an atom.

• An atomic orbital can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus. These functions may

serve as three-dimensional graph of an electron’s likely location.

• The structure of the Periodic table can be understood based on atomic orbitals

.

Slide by: J. Levasseur ©

Atomic Orbitals: The order of filling orbitals • Electrons fill low energy orbitals (closer

to the nucleus) before they fill higher energy ones.– Where there is a choice between

orbitals of equal energy, they fill the orbitals singly as far as possible. Electrons stay as far as they can from each other.

http://www.chemguide.co.uk/atoms/properties/atomorbs.html

Helium 1s2

Movie

Slide by: J. Levasseur ©

One of the amazing phenomenon with electron energy levels is that the 3p high energy sublevel of the third energy level is more energetic than the 4s low energy sublevel of the fourth energy level.This pattern repeats itself and can be seen on the Periodic Table.

Periodic Table, Orbitals & Electron Configuration

Animation

Slide by: J. Levasseur ©

Practice Writing Electron Configuration Notation • Hydrogen........

• Helium….........

• Beryllium…..

• Nitrogen...…

• Silicon……….

• Sulfur…………

• Argon…….…

• Potassium………

• Calcium….

• 1s1

• 1s2

• 1s22s2

• 1s22s22p3

– [He] 2s22p3

• 1s22s22p63s23p2 – [Ne] 3s23p2

• 1s22s22p63s23p4

– [Ne] 3s23p4

• 1s22s22p63s23p6

• 1s22s22p63s23p64s1

– [Ar] 4s1

• 1s22s22p63s23p64s2

– [Ar] 4s2

What elements have the Noble Gas configurations:

• [Ar] 4s1 • [Kr] 5p2

Does P3- have a stable (noble gas configuration?

.

Slide by: J. Levasseur ©

• Radioactivity is the spontaneous breakdown of an atom’s nucleus. This breakdown of atomic nuclei releases certain particles and energy.

• The breakdown of the nucleus can change the atomic mass of an atom; producing isotopes.

• The breakdown of an atom’s nucleus can also cause transmutation of the element. –One element

becomes another due to a change in the atomic number (the number of protons)

Animation

Slide by: J. Levasseur ©Tutorial

The Three Radioactive Emissions & Their Penetrating Power• Alpha Particles are the largest in size of the

emissions, and consequently has the least penetrating power. – Alpha particles are the size of a helium atom's

nucleus.– Alpha radiation: Is easily stopped by paper, foil, or a

few centimeters of air.• Beta Particles are smaller, and therefore have more

penetrating power and danger, than alpha radiation.– Beta particles are the size of an electron, extremely

small. – Beta radiation is stopped by sheet metal, dense

wood, or heavy clothing.• Gamma Radiation does not have a "size" because it

is energy and not matter, (matter has mass and volume, ie. size). Gamma radiation is the most penetrating and most dangerous radiation.– Gamma rays pass through most substances easily. – Blocking gamma radiations takes many centimeters

of lead or a think wall of concrete. Animation

MovieAnimation

Slide by: J. Levasseur ©

Nuclear Fission and Nuclear Fusion

Fission Reaction•Nuclear fission is the splitting of a massive nucleus into photons in the form of gamma rays, free neutrons, and other subatomic particles.

In a typical nuclear reaction involving 235U and a neutron: 235

92U + n 23692U

followed by 236

92U 14456Ba + 89 36Kr + 3n + 177 MeV

Fusion•Nuclear fusion is the reaction in which two or more nuclei combine together to form a new element with higher atomic number (more protons in the nucleus). •The energy released in fusion is related to E = mc 2.

An example is: Deuterium–Tritium reaction. Deuterium and Tritium are both isotopes of hydrogen.

2 1Deuterium + 3 1Tritium 42He + 1

0n + 17.6 MeV

What are alpha decay, beta decay

and gamma decay?If an atom gains a proton but loses no mass, what decay

occurred? If an atom loses two protons and

drops 4 amu, what decay occurred?What is the

difference between fission and fusion?

Fission Animation Fusion Animation

Slide by: J. Levasseur ©

Radon-224 has a half-life of 3.66 days, if you have a 50 gram sample of Radon-224 how much radon-224 will be remaining in

7.32 days?

Half-Life• Half-life is closely related to the

property of Radioactive Decay.• Half-life represents the time taken

for half the atoms in a radioactive substances to undergo decay and change into another nuclear form – Either a radioactive daughter

product or a stable form. – Half-life is the time taken for the

breakdown (decay) of a radioactive sample by half.

– The commonly given the

symbol for Half-life is: t½.

http://www.ionactive.co.uk/glossary/HalfLife.html

An isotope of cesium (cesium-137) has a half-life of 30 years. If 1.0 g of cesium-137

disintegrates over a period of 90 years, how many g of cesium-137 would remain?

Animation

Actinium-226 has a half-life of 29 hours. If 100 mg of actinium-226 disintegrates over

a period of 58 hours, how many mg of actinium-226 will remain?

Thallium-201 has a half-life of 73 hours. If 4.0 mg of thallium-201 disintegrates over a period of 6.0 days and 2 hours, how many

mg of thallium-201 will remain?

Movie

Slide by: J. Levasseur ©

Springfield Central High SchoolChemistryJohn Levasseur

levasseurj@sps.springfield.ma.uscentralscience.net

SECTION 3: THE PERIODIC TABLE

Periodicity

Slide by: J. Levasseur ©

.

Click on circle for interactive Periodic Table

MA State Frameworks

3. Periodicity• Central Concepts:

– Repeating (periodic) patterns of physical and chemical properties occur among elements that define families with similar properties.

– The periodic table displays the repeating patterns, which are related to the atoms’ outermost electrons.

• 3.1 Explain the relationship of an element’s position on the periodic table to its atomic number. – Identify families (groups) and periods on the periodic table.

• 3.2 Use the periodic table to identify the three classes of elements: metals, nonmetals, and metalloids.

• 3.3 Relate the position of an element on the periodic table to its electron configuration and compare its reactivity to the reactivity of other elements in the table.

• 3.4 Identify trends on the periodic table (ionization energy, electronegativity, and relative sizes of atoms and ions).

.

Slide by: J. Levasseur ©

Internet Tutorial by Karl Loren

Periodic Table

Do you remember how to read the Periodic Table?– Each element has an atomic number

based on the number of protons in an atom of that element

– The elements are arranged by increasing atomic number

• The horizontal rows of the Periodic table are known as the periods.  – The horizontal rows of the periodic

Table increase in mass with every element as you move from left to right.

• Groups on the Periodic Table, (aka Families) are the vertical columns– Groups of elements share similar

properties because they share the same valence electron number

• How many protons does an atom of Zinc

have?• How many electrons

does an atom of Sodium have?

• How many neutrons does an atom of

potassium have?

Movie

Animation 3.1