Trends in the periodic table

Question 1

What is covalent radius?

Answer 1

A measure of the size of an atom - half the distance between 2 covalently bonded atoms of an element

Question 2

Going across a period covalent radius _____ because the _________

Answer 2

Decreases, nuclear charge increases pulling electron shells closer together

Question 3

Going down a group covalent radius____ because ________

Answer 3

Increases, the number of filled electron shells increases creating a shielding effect

Question 4

What is the shielding effect?

Answer 4

Each layer of electrons ‘sheilds’ the outer electrons form the positive nucleus so the outer electrons are less strongly attracted to the nucleus

Question 5

Going down a group electronegativity ______ as the ________

Answer 5

Decreases, number of filled electron shells increases shielding the bonded electrons from the nuclear charge

Question 6

Going along a period electronegativity increases as the ________

Answer 6

nuclear charge increases attracting bonded electrons more strongly

Question 7

State the definition of ionisation energy

Answer 7

The energy required to remove one mole of electrons from one mole of gaseous atoms

Question 8

Going down a group the ionisation energy _______ due to __________

Answer 8

Decreases, electron shielding meaning the electron has the weakest attraction to the nucleus due to its distance and number of energy levels

Question 9

Going across a period the ionisation energy ______ due to _________

Answer 9

Increases, the increased nuclear charge holding the outer electrons more strongly so require more energy to remove them