Atomic Theory & electronic structure

Question 1

What did J.J Thomson do?

Answer 1

1. Measured the charge/mass ratio of cathode rays
2. Creates the plum pudding model
3. Discovered electron

Question 2

What did Johnstone Stoney do?

Answer 2

Suggested the name electron in 1891

Question 3

What colour flame does strontium produce?

Answer 3

Red

Question 4

What did William Crookes prove?

Answer 4

Cathode rays travelled in straight lines

Question 5

What did Robert Millikan do?

Answer 5

1. Oil drop experiment- allows charge of electron to be measured accurately

Question 6

What did James Chadwick prove?

Answer 6

Existence of neutrons

Question 7

What did Rutherford prove?

Answer 7

1. Existence of the nucleus and protons

2. Atoms was mostly empty space

Question 8

What was the plum pudding model?

Answer 8

First model of atom. Atom consisted of a (+) sphere w/ electrons randomly distributed inside it.

Question 9

What did John Dalton prove?

Answer 9

1. Atoms are small indivisible particles
2. Atoms of an element are identical
3. Atoms of different elements vary in mass
4. A compound contains atoms of 2 or more elements

Question 10

What is atomic number?

Answer 10

No. of protons in the nucleus (z)

Question 11

What is mass number?

Answer 11

Sum of the no. of neutrons and protons in the nucleus (A)

Question 12

What are isotopes?

Answer 12

Atoms with the same no. of protons but different no. of neutrons

Question 13

What colour flame does potassium produce?

Answer 13

Lilac

Question 14

What is relative atomic mass?

Answer 14

Average mass of an atom relative to one-twelfth the mass of an atom of carbon-12 (Ar)

Question 15

What colour flame does sodium produce?

Answer 15

Yellow

Question 16

What is an energy level?

Answer 16

A region of definite energy within the atom that electrons can occupy

Question 17

What is the hydrogen emission spectrum called?

Answer 17

The Balmer series

Question 18

What does Bohr’s theory show?

Answer 18

1. Electrons occupy fixed energy levels
2. Electrons occupy lowest available energy level (ground state)
3. Electrons can move to higher energy levels if they gain energy (excited state)
4. Excited states are unstable, electrons will return to ground state
5. When this happens, a photon of light is emitted

Question 19

What are the problems with Bohr’s theory?

Answer 19

1. Wave/particle duality
2. Heisenberg’s uncertainty principle
3. Sub-levels and orbitals
4. Only applies to hydrogen

Question 20

What is the Heisenberg uncertainty principle?

Answer 20

States that it is impossible to know both the exact position and velocity of an electron at the same time

Question 21

What is an atomic orbital?

Answer 21

A region where the probability of finding an electron is high

Question 23

What colour flame does barium produce?

Answer 23

Yellow-green

Question 24

What are the types of orbitals?

Answer 24

S
Px
Py
Pz

Question 25

What colour flame does lithium produce?

Answer 25

Deep red

Question 26

What were the observations made of Rutherford’s gold foil experiment?

Answer 26

1. Most particles travel through the foil undeflected
2. Some particles are deflected at small angles
3. Occasionally, a particle travels back from foil

Question 26

What did Rutherford interpret from the gold foil experiment?

Answer 26

1. Atom is mostly empty space
2. Nucleus is positively charged
3. Nucleus carries most of the atom’s mass
4. Nucleus is small and dense

Question 27

What colour flame does copper produce?

Answer 27

Blue-green

Question 27

What shape is a s orbital?

Answer 27

Spherical

Question 28

What shape is a p orbital?

Answer 28

Infinity symbol

Question 29

What is an energy sublevel?

Answer 29

A subdivision of an energy level containing one or more atomic orbitals, all of which have the same energy

Question 30

What is the aufbau principle?

Answer 30

States that:

1) . Electrons will occupy the lowest energy sublevel available
2) . Only 2 electrons can occupy an orbital at the one time
3) . Electrons tend to occupy orbitals of equal energy singly where possible.

Question 31

What is the first ionisation energy?

Answer 31

The first ionisation energy of an element is the minimum energy in kilojoules required to remove the most loosely bound electron from each isolated atom in a mole of the element in its ground state.

Question 32

What is the second ionisation energy?

Answer 32

The second ionisation energy of an element is the minimum energy required to remove the most loosely bound electron form each singly charged positive ion in a mole of these ions.