Structures

Question 1

Properties of giant Ionic lattices (sodium chloride and magnesium oxide)

Answer 1

Crystaline
Brittle
High melting points
Conducts electricity when liquid (ions are free to move and carry charge)

Question 2

Properties of covalent molecular (iodine, carbon dioxide , water)

Answer 2

Low melting and boiling points
Do not conduct electricity
Not soluble in water
Soft when solid

Question 3

Giant covalent properties (diamond)

Answer 3

Very high melting and boiling point
Does not conduct electricity
Insoluble in water
Extremely hard

Question 4

Giant covalent properties (graphite and graphene)

Answer 4

Both do conduct electricity as they have delocalised electrons
Graphite had slippery and soft layers which can slide over each other due to weak forces
Graphene conducts heat and is nearly transparent
Graphene is 100 times stronger than steel but very thin,light and inexpensive

Question 5

Giant metallic structure properties

Answer 5

High melting points,dense and strong (strong metalic bonds)
Conducts electricity
Conducts heat
Malleable
Ductile

Question 6

Allotropes meaning

Answer 6

Different forms of the same element in same physical state

Question 7

Alloys definition

Answer 7

A mixture of two or more elements, at least one of which is a metal, and resulting mixture had metallic properties

Question 8

Alloy examples

Answer 8

Steel is an alloy of iron and gold.
White gold is alloy of gold and silver.
Rose gold is alloy of gold and copper.
Brass is alloy of copper and zinc

Question 9

How to find the % of gold in an alloy

Answer 9

Number of carats divided by 24 x 100