Atomic Structure

Question 1

What is Millikans oil drop experiment?

Answer 1

Oil dropped through charged plates due to electric field. 
X-rays are fed in. 
Forces both up and down in the system.
Oil drops stay static.
Charge can be determined

Question 2

Proton discovery

Answer 2

Fired alpha particles through different gases that were charged.
Dislodged a particle which was same mass and charge of hydrogen.

Question 3

Neutron discovery

Answer 3

Bombarded beryllium with alpha particles

Question 4

Paschen series

Answer 4

Lines in the IR region of the spectrum.

Question 5

Balmer series

Answer 5

Lines in the visible spectrum of hydrogen

Question 6

Lyman series

Answer 6

Lines in the UV spectrum of hydrogen

Question 7

Explain Bohr theory

Answer 7

Lowest state of hydrogen called ground state.
Input of energy excites electron to higher energy level.
Moves to a lower level, light is released.
E2 -E1 = hv
E = hf

Question 8

What is the first ionisation energy

Answer 8

Energy required to remove one electron from each atom in a mole of atoms of an element in the gaseous state.

Question 9

Trend of ionisation energy

Answer 9

Increase across a group.

Decrease down a group

Question 10

State the three rules of quantum numbers.

Answer 10

Aufbau- fill up in order of energy, lowest first.
Hunds- filled singularly first
Paulis- exclusion principle, can’t have two electrons in the same orbital with the same spin

Question 11

How to write quantum numbers?

Answer 11

Principle number - number of shells.
Orbital number - s=0 p=1 d=2 f=3
Magnetic number = px =-1 py=0 pz=1
Spin number = 1/2+ up and -1/2 down

Question 12

What is a transition metal

Answer 12

An element that can form one or more stable ions which has an incompletely filled d - orbital

Question 13

Characteristics of a transition metal

Answer 13

Forms coloured compounds.
Used in catalysts.
Variable valancy