1. n = 2
n = 1
“ground state”
n = 3
n = 4
n = 5
Properties of Matter

2. Atomic Structure (in the book) (negatively charged)
When the number of electrons = the number of protons, it is a neutral “atom”

3. Atomic Terminology: Atomic number Atomic Mass number (“atomic weight”)
Isotope
98.9%
1.1%
radioactive

4. What is the atomic number of nitrogen?
D) 12
E) 14

5. What is the atomic mass number of nitrogen?
D) 12
E) 14

6. What would the charge be of a nitrogen ion with 5 electrons?

7. Phases of matter and Phase changes: Stars Ionization Sublimation
Condensation
Evaporation
Freezing
Melting
Deposition

8. Phase transitions are always happening
For example, water molecules are constantly evaporating from and condensing on the ocean (and lakes, streams, puddles, etc.)
The balance depends on temperature and the pressure of water vapor already in the air.

9. When acetone evaporates, it ends up in which phase?
A) Solid
B) Liquid
C) Gas
D) Plasma

10. Before carbon dioxide sublimates, it is in which phase?
A) Solid
B) Liquid
C) Gas
D) Plasma

11. Energy Levels in Atoms (Electron energy levels) In the atom (vaguely!)
The energy levels of the electrons
In hydrogen
n = 1
“ground state”
n = 2
n = 3
1 eV = 1.6 x J
n = 4
n = 5

12. But the photon will be absorbed only if its energy
Energy Levels in Atoms
(Electron energy levels)
When an electron absorbs a photon …
… the atom’s energy goes up
n = 1
“ground state”
n = 2
n = 3
n = 4
n = 5
But the photon will be absorbed only if its energy
exactly matches the difference between levels

13. Energy Levels in Atoms (Electron energy levels)
When an electron emits a photon …
… the atom’s energy goes down
n = 1
“ground state”
n = 2
n = 3
n = 4
n = 5
The photon’s energy will exactly match the difference between levels

14. What is the energy of the photon given off during the transition shown?
A) eV
B) eV
C) eV
D) eV
E) eV

15. This leads to a specific spectrum for hydrogen
Given all the different energy levels available, there are a LOT of possible photons energies that can be given off. UV
Vis IR
This leads to a specific spectrum for hydrogen

16. Every atom / ion / molecule has a unique set of energy levels
And so each has a unique spectrum!
This is how we can know what things in space are made of.

17. Astro-Cash Cab!
Cale
Zach
Isabel
Brittany L.
Kyle

18. 1) What is the charge of a carbon ion with 5 electrons?–5 –1 +1 +2

19. 2) When an electron goes through the transition shown below, does it absorb or emit a photon?

20. 3) 22Na, 23Na, and 24Na are some of the different ____________ of sodium.

21. 4) True or False ?
When nitrogen gas turns into a liquid, that process is called sublimation.