atomic theory - weebly · 2018-02-08 · atomic theory. the theory that all matter is made up of...
TRANSCRIPT
Science 10Developed by M.Poonia & V.Sidhu
Atomic Theory & Bonding
What we’ll be looking at….
- Atom- Protons, neutrons, electrons- Nucleus
- Periodic Table- Trends
- Bohr Diagrams- Forming Compounds
This is what water looks like at an atomic level!
Which of these is smallest?
PLICKER QUESTION
What is the smallest thing you can think of?
Questions to consider:
- When you touch the air in front of you, what are you touching?
- What does it mean if a surface feels smooth or soft?
Recall:
- In grade 8/9 you learned that an atom is the smallestparticle of any element that retains the properties of the element.
What is an atom?
What do you think the word “Atom” means?
PLICKER QUESTION
Example (Apple)
The word “atom” is Greek for uncuttable
What is an atom?- They are building blocks- Very very very very small
- If you could up 50 million atoms, the line would be about 1 cmlong
- The particles that make up an atom are called subatomic particles
- Atoms are chemically the simplest substance and cannot be broken down using chemical methods. Atoms can only be changed into other elements using nuclear methods (more next unit).
What is an atom? ContinuedIf you want to build molecules, you will need atoms of different elements
- Elements are the alphabet in the language of molecules
- An element is a substance consisting of atoms which all have the same number of protons.
- Each element is a little bit different from the rest- The periodic table shows all the elements that have
been discovered
Atomic Theory
The theory that all matter is made up of tiny indivisible particles (atoms). According to the modern version, the atoms of each element are effectively identical, but differ from those of other elements, and unite to form compounds in fixed proportions.
Common Elements
What’s the big deal with atoms? (Why should you care?)
You could start really small...- Particles of matter- Atoms- Molecules- Macromolecules- Cell organelles- Cells- Tissues- Organs- Systems- Organisms
- Populations- Ecosystems
- Biomes- Planets
- Systems with Stars- Galaxies
- The Universe...And finish really big.
Subatomic ParticlesThese are the 3 main parts that make up an atom:1. Neutrons (neutral)2. Protons (+)3. Electrons (-)
Nucleus
Name Electric
Charge
Location in
Atom
Relative
Mass
Proton (p) 1+ Nucleus 1836
Neutron (n) 0 Nucleus 1837
Electron (e) 1- Surrounding
the Nucleus
1
Protons, Neutrons & Electrons
Nucleus...- Is in the center of an atom- The protons and neutrons are located here- For smaller atoms (<30 protons), the # of neutrons and protons are
roughly equal in the nucleus- The electric charge on any nucleus is always positive (because
protons are positively charged, and neutrons are not electrically charged)
Nucleus continued...
- Atomic number of a neutral atom = # of protons = # of electrons
- Atomic number always identifies with the element to which the atom belongs.
Ex: all atoms with an atomic number 8 are oxygen atoms, & all oxygen atoms always have 8 protons in nucleus
Understanding each element:
4+
Ion charge: created
by the gain or loss of
one or more electrons
from an atom
The information provided on your periodic table can be used to determine the number of each
subatomic particle in the atoms of that element.
Practice:
How many protons are in Aluminum?
If Aluminum is neutral, how many electrons does it have?
How many neutrons does Aluminum have?
Formula...
For any element:Number of Protons = Atomic NumberNumber of Electrons = Number of Protons = Atomic NumberNumber of Neutrons = Mass Number - Atomic Number
Element Element
Symbol
Atomic # Atomic
Mass
# of
protons
# of
neutrons
# of
electrons
Carbon C 6 12 6 6 6
Sodium 11 23
55 25
56 30
14 14
Oxygen O 8 16 8 8 8
52 76
40 18
15 31 15
45 35
PLICKER QUESTION
Element Element
Symbol
Atomic # Atomic Mass # of protons # of neutrons # of electrons
Carbon C 6 12 6 12-6 = 6 6
Sodium Na 11 23 11 12 11
Manganese Mn 25 55 25 30 25
Iron Fe 26 56 26 30 26
Silicon Si 14 28 14 14 14
Oxygen O 8 16 8 8 8
Tellurium Te 52 128 52 76 52
Argon Ar 18 40 18 22 18
Phosphorus P 15 31 15 16 15
Bromine Br 35 80 35 45 35
Ion Formation
Ions: When atoms gain or lose electrons, they become electrically charged particles. (Usually metals lose electrons).
If they lose electrons (and so become positive), they form positively charged ions called cations.
Example: Al 3+ means that aluminum has LOST three electrons.
Ion Formation Continued
Multivalent: some metals form ions more than one way Ex. Fe 2+/3+
If they gain electrons, (and so become negative), they form negatively charged ions called anions. (Usually non-metals gain electrons).
Example: Cl - means that chlorine has gained an electron.
Think Pair Share...Find the formula for finding the following information:
Element
Name
Atomic # Ion Charge # of
Protons
# of
Electrons
# of
Neutrons
potassium 19 1+ 19 18 20
iron 26 2+
How would you create an atom that is neutral?
PLICKER QUESTION
Practice
Do questions 1-3 on page 60 in your workbook.