Atomic Structure

Question 1

Early Greek Model (400 BC)

Answer 1

• Democritus
• Matter cannot be continuously subdivided
• Used the term “Atomos” (indivisible)
• The model became unpopular when Plato, Aristotle, and Socrates disagreed

Question 2

Dalton’s Model

Answer 2

1. Matter is composed of tiny particles called atoms.
2. Atoms are indestructible and indivisible.
3. Atoms of the same element are identical in size, mass, and properties.
4. Atoms of different elements can combine into compounds.

Question 3

Thomsons Plum Pudding Model

Answer 3

• Used a cathode ray tube for experiments
• Discovered electrons
• Said the atom was neutral due to a positive jelly-like sphere around the electrons

Question 4

Rutherfords Model

Answer 4

• Dense, positively charged center of the atom

- Atom is mostly empty space

Question 5

Bohr’s Planetary Model

Answer 5

• Electron orbit the nucleus in energy levels
• energy level n = 1 is closest to the nucleus
• Electrons gain energy to become excited and lose to produce light spectra

Question 6

Heisenberg / Schrodinger Model

Answer 6

• Current model
• Wave mechanical / Cloud Model
• impossible to know the exact location of an electron
• Atom = neutral
• Protons + Neutrons = Nucleus
• Orbitals propose the probable location of e-

Question 7

Proton

Answer 7

Positively charged particle

Question 8

Neutron

Answer 8

No Charge

Question 9

Electron

Answer 9

Negatively charged particle

Question 10

The # of protons is called?

Answer 10

The atomic number

Question 11

Where are protons and neutrons located?

Answer 11

The nucleus

Question 12

Why do we need neutrons?

Answer 12

Without them, the protons would repel from each other

Question 13

How to find the # of neutrons

Answer 13

mass # - atomic #

Question 14

Nucleons

Answer 14

particles that reside in the nucleus

Question 15

Weighted Average Equation

Answer 15

(% abundance x atomic mass) + add however many it asks

Question 16

Orbitals

Answer 16

Most probable location for an electron

Question 17

Does energy level n=1 (first orbital) have a lot of energy

Answer 17

No, it has the least amount. As you go outwards for orbitals you get more

Question 18

Orbital electron maxium

Answer 18

orbital #electrons

1 2
2 8
3 18
4 32

Question 19

Where to find electron configuration on the periodic table

Answer 19

Bottom left corner in a box of an element

Question 20

Last orbital

Answer 20

Valence shell

Question 21

Valence electrons

Answer 21

• Outermost
• determine the reactivity of an atom
• Nevermore than 8!

Question 22

Lewis Dot diagrams

Answer 22

• Use # of electrons in the valence shell

- Last # for electron configuration

Question 23

When taking away e- where do you take away from?

Answer 23

The valence shell

Question 24

Nuclear charge

Answer 24

Charge of the nucleus

Question 25

Excited-state

Answer 25

- Gain energy - When an electron gains energy it moves or “jumps” to a higher energy level - The electron configuration changes to show where electrons moved

Question 26

Ground State

Answer 26

- An atom is in its ground state when electrons are filled into the lowest energy levels possible - Atoms in the ground state are on the periodic table

Question 27

An excited atom is

Answer 27

unstable and will quickly “fall” back to the ground state

Question 28

The light emitted as atoms go from excited to the ground state are called:

Answer 28

spectral lines, atomic spectra, or bright-line spectrum

Question 29

The nucleus of an atom

Answer 29

contains most of the mass of the atom