Atomic Structure, Electronic Configuration and Periodicity

Question 1

Atomic number

Answer 1

The number of protons in the nucleus of an atom of a particular element

Question 2

Mass number

Answer 2

The number of protons and neutrons in the nucleus of an atom of a particular element

Question 3

Isotope

Answer 3

Atoms with the same number of protons but with different numbers of neutrons

Question 4

Relative atomic mass

Answer 4

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

Question 5

Relative isotopic mass

Answer 5

The mass of an atom of a particular isotope relative to 1/12 of the mass of carbon 12

Question 6

Molecular ion peak

Answer 6

The peak with the highest m/z ratio in the mass spectrum

Question 7

1st ionisation energy

Answer 7

The energy required to remove an electron from each atom in one mole of atoms in the gaseous state

Question 8

Equation for 1st ionisation energy

Answer 8

E(g) → E+(g) + e-

Question 9

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 orbitals singly before pairing takes place

Question 11

Pauli Exclusion Principle

Answer 11

Two electrons cannot occupy the same orbital unless they have opposite spins

Question 12

Periodicity

Answer 12

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