Group 2 physical and chemical properties

Question 1

What is atomic radius

Answer 1

• the distance between the nucleus and the outermost electrons

Question 2

What is the trend in atomic radius down group 2

Answer 2

-atomic radius increases down group 2

Question 3

Why does atomic radius increase down group 2

Answer 3

-atoms get larger
-due to extra shell added down the group

Question 4

What is 1st ionisation energy

Answer 4

The energy required to remove 1 mole of electrons from 1 mole of atoms to form 1 mole of 1+ ions in the gaseous state

Question 5

Write the general equation for first ionisation energy

Answer 5

Element(g)—>Element+(g) +e-

Question 6

Why does 1st ionisation energy decrease down the group

Answer 6

-1 more electron shell for each element down the group
-so more electron shielding
-outer electron hence further away from positive nucleus
so weaker efoa between psotive nucelus and -ve valence electron
-so easier to lose that electron

Question 7

What is melting point

Answer 7

The temperature where the forces between particles in a solid lattice weaken and particles separate

Question 8

What is the trend in melting point down group 2

Answer 8

-Melting point GENERALLY decreases down group 2

Question 9

Why does melting point decrease down group 2

Answer 9

-metallic bonding weakens
-due to increase in atomic size
-so distance between positive ions and delocalised electrons is greater
-so weaker EFOA between positive ions and delocalised electrons
-so less energy required to break bonds

Question 10

Where is there a blip in the melting point trend for group 2

Answer 10

At magnesium

Question 11

Why is there a blip at magnesium
in melting point for group 2

Answer 11

Due to differences in metallic crystal structures

Question 12

does ionic radius increase or decrease down group 2

Answer 12

ionic radius increases down group 2

Question 13

what is reactivity

Answer 13

-a measure of how readily atoms lose their outer electrons

Question 14

why does reactivity increase down group 2

Answer 14

-atoms get bigger
-and increase in number of shells
-more electron shielding
weaker attraction between valence electron and positive nucleus
-easier to lose outer electron (less energy needed)

Question 15

what happens going down group to the following
-atomic radius
-first ionisation energy
-melting point
=reactivity

Answer 15

-atomic radius-increases
-first ionisation energy decreases
-melting point decreases
-reactivity increases