1. Day 23 – Daily Starter
What do you remember about the structure/ make-up of an atom?
(“IDK” is not an answer)

2. Today’s Topic: Atomic Structure
Unit 2 Chemistry Review
Today’s Topic:
Atomic Structure

3. Niels Bohr (1913) Bright-Line Spectrum
tried to explain presence of specific colors in hydrogen’s spectrum

4. Niels Bohr (1913) Energy Levels Planetary Model
electrons can only exist in specific energy states
Planetary Model
Electrons move in circular orbits with specific energy levels

5. Erwin Schrödinger (1926) Quantum mechanics Electron cloud model
electrons can only exist in specified energy states
Electron cloud model
orbital: region around the nucleus where e- are likely to be found

6. Electron Cloud Model (orbital)
Erwin Schrödinger (1926)
Electron Cloud Model (orbital)
dots represent probability of finding an e- not actual electrons

7. James Chadwick (1932) Discovered neutrons Joliot-Curie Experiments
neutral particles in the nucleus of an atom
Joliot-Curie Experiments
based his theory on their experimental evidence

8. revision of Rutherford’s Nuclear Model
James Chadwick (1932)
Neutron Model
revision of Rutherford’s Nuclear Model

9. II. Electron Cloud Model Orbital Energy Levels Bohr Model Diagrams

10. A. Orbital
Region where there is 90% probability of finding an electron.
Can’t pinpoint the location of an electron.
Density of dots represents degree of probability.

11. A. Orbital
Orbitals have different shapes.

12. B. Energy Levels Electrons can only exist at certain energy levels.
Low energy levels are close to the nucleus.
Each energy level (n) can hold 2n2 electrons.

13. C. Bohr Model Diagrams
Simplified energy levels using Bohr’s idea of circular orbits.
Can replace with: 3p 4n
Lithium
Atomic #: 3
Mass:
# of p: 3
# of e: 3
# of n: 4 e- e- p n
Maximum e-
Level 1 2e-
Level 2 8e-
Level 3 18e-
Level 4 32e- e-

14. C. Bohr Model Activity Get with your assigned unit partner
Choose a number between 1 & 18.
Find your element by the atomic number you picked.
Draw a Bohr Model diagram for your element.
Refer to the mass listed on the table and subtract the atomic # to find the # of neutrons.
Abbreviate the # of ‘p’ and ‘n’ in the nucleus.
Have your partner check your drawing.
Repeat with 2 new elements (each partner draws 3)

15. In Class work – Show before you Go
The Atoms Family Atomic Math Challenge
A Review of the Periodic Table 6 C
Carbon 12
Atomic number = 6
Symbol = C
Name = Carbon
Average atomic Mass = 12