Periodic Table

Question 1

Trends across a period

Answer 1

Atom radius DECREASES
Ionisation energy INCREASES
Electronegativity INCREASES
Electron shielding stays the same

Question 2

Trend down a group

Answer 2

Atomic radium INCREASES
Ionisation energy DECREASES
Electronegativity DECREASES
Electron shielding INCREASES

Question 3

Why does the atomic radius DECREASE across a period?

Answer 3

Nuclear charge increases as number of protons in the nucleus increases
Electrons are attracted more strongly to the nucleus
Same shell

Question 4

Why does the atomic radius INCREASE down a group?

Answer 4

Energy level increases
Electron shielding increases
Weaker attraction between nucleus and valence electrons
Shells increase

Question 5

Define ATOMIC MASS

Answer 5

The average mass of an atom of an element compared to 1/12 of a carbon-12 atom