Structure 3.1

Question 1

Elements in the same group

Answer 1

Have similar chemical properties

Question 2

Atomic radius

Answer 2

Half the distance between neighbouring nuclei

Question 3

Atomic radii trend across a period

Answer 3

Nuclear charge increases, electrostatic attraction increases, decrease in radii

Question 4

Atomic radii trend down a group

Answer 4

Number of occupied electron shells increases down a group, increasing atomic radii (more electron shells also provides sheilding)

Question 5

Positive ions

Answer 5

Same number of protons, lose electrons, small than the atom

Question 6

Isoelectric positive ions

Answer 6

Decreases in size across a period as the number of electrons remains constant, nuclear charge increases

Question 7

Negative ions

Answer 7

Same number of protons, gain electrons, larger than the atom

Question 8

Isoelectric negative ions

Answer 8

Decrease in size cross a period as number of electrons remains constant and nuclear charge increases

Question 9

Ionization energy

Answer 9

Enthalpy change when an electron is removed from an atom in the gaseous state. Endothermic

Question 10

Ionization energy across a period

Answer 10

Increase in nuclear charge increases the attraction between the outer electron and the nucleus, making electrons more difficult to remove (generally increases)

Question 11

Ionization energy down a group

Answer 11

Electron removed is from the valence shell. Nuclear charge is similar due to the shielding, so increased distance reduces the attraction and decreases ionization energy.