Boron Family

Question 1

What comprises the Boron Family

Answer 1

Boron, Aluminium, Gallium, Indium and Thallium

Question 2

What is the physical property of a Boron?

Answer 2

Black solid, Hard, Non-metallic, Exist in allotropic (Different Forms)

Question 3

Down the Boron Family, does the density increase/decrease and why?

Answer 3

The Density increases because the size of the atom increases

Question 4

Down the Boron Family, does the Boiling Point increase of decrease?

Answer 4

• Decrease
• Size of atom increase
• Attraction force weak

Question 5

Down the Boron Family, does the Melting point increase or decrease?

Answer 5

The Melting Point will decrease until Gallium, Then it will increase from Indium to Thallium

Question 6

What is the magic number?

Answer 6

8, 18, 18, 32

Question 7

Why is there a Decreasing order of Ionisation Enthalpy in the Boron Family?

Answer 7

• It is because the entry of the d orbital between Ga and Al and the entry of f orbital between In and Te

Question 8

What is the increasing order of the atomic radii in the Boron Family and why is it like that

Answer 8

• Ba, Ga, Al, In, Te
• It is because of the entry of the d orbital at the the Ga element to TI
• The d orbital has poor shielding effect compared to s and p orbital
• Poor shielding effect causes electrons to be held more firmly which causes the atomic radii to be smaller and IE high
• Called as d block contraction

Question 9

What is the physical properties of Ga, In and Te?

Answer 9

• Reactive
• Soft
• Obtained by electrolysis of salt solution
• Low in melting

Question 10

What is the Electron Configuration of the boron family?

Answer 10

• Ns2 np1
• N = number of shells

Question 11

What is the formal charge of each of the elements in the Boron family?

Answer 11

• Br (3+)
• Al (3+)
• Ga (3+)
• In (1+, 3+)
• Te (1+)

Question 12

What is the non-metal in the boron family?

Answer 12

Boron

Question 13

Going down Group 13 does the inert pair effect increase or decrease?

Answer 13

Increase

Question 14

What are the properties of Ga, In, and TI

Answer 14

• Reactive
• Soft and silvery appearance
• Low in abundance

Question 14

Why is there differences between the stability of some of the elements’ oxidation states?

Answer 14

• Inert pair effect increases down the group
• The electrons in s2 orbital becomes progressively inert which causes the atom to hold onto the electrons tighter and not wanting to let them go
• TI + is more stable than TI 3+

Question 15

Are most of these compounds ionic or covalent?

Answer 15

Its borderline. Most are covalent when anhydrous and ionic when in solution form

Question 16

What type of oxide is boron oxide (B2O3)

Answer 16

Acidic

Question 17

Give properties of aluminium

Answer 17

1. Malleable, ductile
2. Resist corrosion (Layer of aluminium oxide on surface)
3. Strong when alloyed

Question 18

What is the third most abundant element?

Answer 18

Aluminium

Question 19

In what form is Aluminium usually found?

Answer 19

Bauxite (Al2O3) or Cryolite

Question 20

How is Polymeric borate ions formed? (Stable ion)

Answer 20

By reacting Br2O3 with metal oxide (G1&G2)

Question 21

Characteristics of boron hyride

Answer 21

• Low Melting/Boiling Point
• Burn spontaneously
• Gaseous