Agenda

• Elements/AT/Atoms, Ions, & Isotopes

• Homework Check

• Song

• Notes

• Go over Test

• Homework

Who developed an atomic theory?

John Dalton

What were his four points?

Who found the e-?

Thompson

Who found the n0?

Chadwick

Who found the p+?

Goldstein

Who discover the nucleus?

Rutherford

What experiment did he do?

gold foil experiment

What type of model did Bohr develop for the atom?

planetary model

Who came up with the idea of an e- cloud?

Schrödinger

141466CC

pp++

nnoo

ee--

2072078282PbPb+4+4

pp++

nnoo

ee--

Atomic Theory Polka• Dalton, Thomson, Rutherford and Bohr.

Schrödinger and Heisenberg, and many, many more. Used their brains to venture in the realm of inner space and found the world of the atom was a weird and wondrous place.

• Dalton did experiments and said, “I think it’s clear, atoms are tiny indestructible spheres.”

• Thomson worked with cathode rays and said, “I disagree. A plum-pudding model makes much more sense to me.”

• A new chapter in atomic theory started to unfold when Rutherford played around with atoms made of gold. When a few of his alpha particles came bounding back, he hypothesized a nucleus had knocked them off the track.

• Dalton, Thomson, Rutherford and Bohr. Schrödinger and Heisenberg, and many, many more. Used their brains to venture in the realm of inner space and found the world of the atom was a weird and wondrous place.

• Bohr saw spectral lines for hydrogen and said, “It seems to me.. Electrons move in orbits with specific energies.”

electron

neutron

proton

• Heisenberg said, “Forget it, there’s no way to know the orbit or a path, where the electron’s gonna go.”

• Schrödinger used lots and lots of fancy mathematics, and made a model of the atom based on quantum mechanics. It has orbitals and those are based on probability. The atom is a fuzzy blob of pure uncertainty.

• Dalton, Thomson, Rutherford and Bohr. Schroedinger and Heisenburg, and many, many more. Used their brains to venture in the realm of inner space and found the world of the atom was a weird and wondrous place.

Homework# Isotope Nuclide A # M # #p+ #n0 #e-

1 Copper-65 6529Cu+ 29 65 29 36 28

2 Lithium-7 73Li+ 3 7 3 4 2

3 Neon-20 2010Ne 10 20 10 10 10

4 Oxygen-16 168O-2 8 16 8 8 10

5 Chlorine-36 3617Cl- 17 36 17 19 18

6 Scandium-45 4521Sc+3 21 45 21 24 18

7 Calcium-40 4020Ca+2 20 40 20 20 18

8 Bromine-80 8035Br- 35 80 35 45 36

9 Tellurium-128 12852Te-2 52 128 52 76 54

10 Aluminum-27 2713Al+3 13 27 13 14 10

Homework# Isotope Nuclide A # M # #p+ #n0 #e-

11 Zinc-65 6530Zn+2 30 65 30 35 28

12 Iron-56 5626Fe+2 26 56 26 30 24

13 Iron-55 5526Fe+3 26 55 26 29 23

14 Phosphorus-31 3115P-3 15 31 15 16 18

15 Xenon-131 13154Xe 54 131 54 77 54

16 Magnesium-24 2412Mg+2 12 24 12 12 10

17 Carbon-12 126C-4 6 12 6 6 10

18 Hydrogen-3 31H+ 1 3 1 2 0

19 Sodium-24 2411Na+ 11 24 11 13 10

20 Hydrogen-1 11H- 1 1 1 0 2

Bohr’s Model

Date

Planetary Model

• Bohr described the atom through a planetary model

• e- orbit the nucleus like planets around the sun

• They are located in specific energy levels or shells in concentric circles like layers of an onion

Shells

• 1st shell• 2nd shell• 3rd shell• 4th shell

• 2• 8• 8 (18)• 8 (32)

• Each shell has a specific number of electrons it can hold

11H

126C

2311Na

Practice

Lewis Dot Structure

• Lewis came up with a simple method of showing the outer shell of an atom

• First write the symbol of the element

• Next figure out how many e- are in the outer shell

• Finally put that many dots around the symbol

Examples

H

C

Na

Na+

2311K+

K

168O-2

O

3517Cl-

Cl

4018Ar

Ar

3216S-2

S

Transitional Metals

• Transitional metals put their first two e- in the nth shell (where n is the row number)

• They then put the rest of the electrons back into the n-1 shell

Example

• Sc has 21 e-

• The first 18 work the same as we have been doing

• That leaves 3 e-

Example

• Sc is in the 4th row so we put two of the remaining electrons in the 4th shell

Example

• Since it is in the 4th row n-1=3

• So we put the last electron in the 3 shell