atomic theory - weebly · 2018-02-08 · atomic theory. the theory that all matter is made up of...

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.

Atoms are all around us & in us

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

Why do we care about atoms?

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.

From Simple to Complex

http://scaleofuniverse.com

Can we see atoms if they are so small?

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

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rts of a

n A

TO

M

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

R

E

V

I

E

W

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.