Chemistry

Question 1

What are nano-materials and what are they used for?

Answer 1

Nano-Materials are very small (one nano metre = one thousand millionth of a metre

Question 2

What are macromolecules?

Answer 2

Macromolecules are formed by giant covalent bonds e.g. Diamond, Graphite etc

Question 3

Why do metals conduct electricity?

Answer 3

The bonding in metals creates delocalised electrons (free to move and pass on electrical curren)

Question 4

What is the bonding like in graphite?

Answer 4

Each carbon atom forms 3 covalent carbon-carbon bonds with the carbons around them creating a sea of delocalised electrons which will pass an electriclal current

Question 5

Which group of the periodic table do not form ions?

Answer 5

Noble gases do not form ions as they already have an outer shell

Question 6

What is a smart alloy and why are they used?

Answer 6

Smart alloys can return to their original shape after being deformed - e.g. glasses and braces

Question 7

What are the masses and charges of these parts of an atom?
Proton
Neutron
Electron

Answer 7

Protons = +1 charge, 1 mass
Neutrons = Neutral charge, 1 mass
Eletrons = -1 charge, 1/2000th mass

Question 8

All atoms of a particular element all have the same number of what?

Answer 8

Protons

Question 9

What happens to the electrons of 2 atoms when they chemically react?

Answer 9

During a chemical reaction electrons are either given away, taken or shared

Question 10

What is an isotope?

Answer 10

An isotope is an atom with a different amount of neutrons

Question 11

What is an alloy and why are they used?

Answer 11

Alloys are mixtures of metals with other elements e.g. iron + carbon = steel

They have a combination of properties

Question 12

How many electrons can occupy the 1st and 2nd shell?

Answer 12

2 in the first shell and 8 in the second