Topic 1: Atomic structure and the Periodic table

Question 1

What is the relative mass of an electron? and position in the atom?

Answer 1

1/1840

-Energy levels surrounding the nucleus

Question 2

What is the relative mass and position in the atom of protons and neutrons?

Answer 2

1

-In the Nucleus

Question 3

What is meant by atomic number?

Answer 3

Number of protons in the nucleus of an atom of that element

Question 4

What is meant by Mass number?

Answer 4

Sum of the protons and number of neutrons in the nucleus of that atom

Question 5

What are Isotopes?

Answer 5

Atoms with the same amount of protons (same element) different amount of neutrons

Question 6

Relative atomic mass

Answer 6

The weighted mean mass of an atom of an element compared to 1/12 the mass of an atom of carbon-12

Question 7

Relative isotopic mass

Answer 7

Mass of an individual atom of an isotope relative to 1/12 the mass of an atom of carbon-12

Question 8

Molecular ion peak

Answer 8

Peak with the HIGHEST m/z ratio in the mass spectrum

Question 9

Definition of an Orbital

Answer 9

a region within an atom that can hold up to two electrons with opposite spins

Question 10

Hund’s rule

Answer 10

electrons will occupy the orbits singly before pairing up

Question 11

Pauli’s EXCLUSION Principle

Answer 11

Two electrons cannot occupy the same orbital unless they have opposite spins (↑↓)

Question 12

First Ionisation energy

Answer 12

X(g)➝X+(g) + e-

The energy required to remove an electron from each atom in ONE MOLE of atoms in the GASEOUS state

Question 13

Second Ionisation Energy

Answer 13

X+(g)➝X2+(g) + e-
The energy required to remove an electron from each +1 charged positive ion in ONE MOLE of positive ions in the GASEOUS state

Question 14

What 3 Factors influence ionisation energies in an atom?

Answer 14

• proton number
• electron shielding
• electron orbitals (subshells)

Question 15

What 3 Factors affect the energy of an electron?

Answer 15

• It’s orbital
• Nuclear charge
• Shielding

Question 16

What is the trend in ionisation energies across a period? Explain why.

Answer 16

• Across a period
• Nuclear charge increases
• This leads to an increased attraction between the nucleus and the electron
• This would mean a decrease in energy for the electron
• THEREFORE MORE ENERGY IS NEEDED to remove it
• Therefore an increase in first ionisation energy

Question 17

What is the trend in ionisation energies down a group?

Answer 17

• Decreases
• Because of a new quantum shell added
• This increases the electron shielding
• Increasing the distance between the valent electrons and the nucleus
• This decrease the attractive force felt by the further electrons
• This increases the energy of the outermost electron
• Making it easier to remove an electron

Question 18

Evidence for quantum shells

Answer 18

-Successive ionisation energies

Question 19

Shape of a s-orbital

Answer 19

Spherical

Question 20

Shape and orientations of a p-orbital

Answer 20

Hourglass (3 orientations) (x, y, z)

Question 21

How many electrons can a s, p, d subshell hold?

Answer 21

s: 2
p: 6
d: 10

Question 22

What determines the chemical properties of an element?

Answer 22

The electron configuration of the element

Question 23

Periodicity

Answer 23

Regular repeating pattern of atomic, physical and chemical properties with increasing atomic number