1. Atomic Structure

2. Learning Goals Identify and describe particles which comprise atoms.
Compare atoms and contrast forces inside.
Determine subatomic particles from atomic number and mass number.

3. Bellringer
What is an atom?
What does an atom look like?

4. Body Essentials Protein Lipids (Fat) Carbohydrate
Macromolecules that aid in human performance.
To understand their functions we must understand their structure.

5. Structure of the Atom
In order to understand atoms, we need to understand the idea of electric charge.
We know of two different kinds of electric charge and we call them positive and negative.

6. Electric charge in matter
We say an object is electrically neutral when its total electric charge is zero.

7. Nucleus- small dense center of the atom.
protons and neutrons
Electron Cloud- outer part of atom where the electrons lie.

8. Inside an atom
The mass of the nucleus determines the mass of an atom!!
protons and neutrons are much larger and more massive than electrons.
In fact, a proton is 1,836 times heavier than an electron! WOW!

9. Proton and Neutron weigh almost the same

10. Force inside atoms
Electrons are bound to the nucleus by the attractive force between electrons (-) and protons (+).

11. Force inside atoms What holds the nucleus together?
There is another force that is even stronger than the electric force.
We call it the strong nuclear force.

12. How are atoms of various elements different?
The atoms of different elements contain different numbers of protons in the nucleus.
Because the number of protons is so important, it is called the atomic number.

13. SUPER SUPER IMPORTANT! Protons define the element!
CAN’T CHANGE NUMBER OF PROTONS!
Hydrogen ALWAYS has 1 proton
Helium ALWAYS has 2 protons
Chlorine ALWAYS has 17 protons

14. What info can we gather from the Periodic Table?
12.011 6
Atomic Number =
# of protons / # of electrons
Symbol of element
Atomic Mass =
(# of protons) + (# of neutrons)

15. Check for Understanding!
How many protons, neutrons, and electrons are in iron given the periodic table?
Answer:
26 protons, 26 electrons, and 30 neutrons

16. You may need the Periodic Table to fill in this chart
Calculating P, N, and E
Symbol
Mass
Proton
Neutron
Electron B 6 24 11 Pb
207
You may need the Periodic Table to fill in this chart