P1 - Bonding, Structure, And Properties Of Matter

Question 1

Do metals form a positive or negative ion?

Answer 1

Positive - because they lose electrons (losing negativity so they become positive :D )

Question 2

Do non-metals for positive or negative ions?

Answer 2

Negative - they gain electrons (gain negativity so become negative)

Question 3

What is ionic bonding?

Answer 3

When a metal and non-metal react together, and the metal transfers electrons to the non-metal so that they both have full outer shells. They are then strongly attracted to one another by electrostatic forces.

Question 4

How do you show ionic compounds as a diagram?

Answer 4

You use a dot and cross diagram. The dots representing the electrons on one element and the crosses representing the electrons on the other element.

Question 5

What kind of structure do ionic compounds form?

Answer 5

They form giant ionic lattice structures.

Question 6

What are the properties of ionic compounds?

Answer 6

• High melting and boiling points
• When solid they can’t conduct electricity because they are so tightly packed, but when a liquid they can carry electric current
• Dissolve easily in water

Question 7

What is covalent bonding?

Answer 7

When two non-metals bond together by sharing their electrons so that each has a full outer shell. They are attracted by electrostatic forces.

Question 8

How do you show covalent bonding in a diagram?

Answer 8

Using a dot and cross diagram and overlapping the outer shells. In the overlapped area will be the electrons that are shared between the two elements.

Question 9

Define a simple molecular substance

Answer 9

Substances that are made up of molecules containing few atoms joined together by covalent bonds.
Examples: hydrogen, chlorine, oxygen, nitrogen, methane, water, hydrogen chloride

Question 10

What are the properties of simple molecular substances?

Answer 10

• Very strong covalent bonds
• Forces between molecules are weak
• Low boiling and melting points
• Gases or liquids at room temperature
• Don’t conduct electricity as there are no free electrons and they aren’t charged

Question 11

What is different about polymers that are not the same in simple covalent molecules?

Answer 11

The intermolecular forces in a polymer are larger than those in simple covalent molecules, meaning more energy is needed to break them, so they are solid at room temperature even though they use covalent bonding.

Question 12

Define giant covalent structure

Answer 12

These are called macromolecules where all the atoms are bonded to each other by strong covalent bonds. They never conduct electricity.
Examples: diamond, graphite, silicon dioxide

Question 13

What are the properties of diamond?

Answer 13

• Four covalent bonds
• Really hard
• Very High melting point
• Doesn’t conduct electricity as there are no free electrons

Question 14

What are the properties of graphite?

Answer 14

• Three covalent bonds (hexagon shapes)
• In layers with cross links between them
• Soft and slippery
• High melting point
• Each carbon atom has one delocalised electron so it conducts electricity and thermal energy

Question 15

What are the properties of fullerenes?

Answer 15

• Carbon shaped like closed tubes or hollow balls
• Can be pentagons, hexagons, or heptagons
• Can be used to cage other molecules (deliver drug into body)
• Large surface area (good catalysts)

Question 16

Define metallic bonding

Answer 16

When metals bond the outer shell’s electrons become delocalised and the electrostatic attraction holds the atoms together in a regular structure.

Question 17

What are alloys?

Answer 17

These are mixtures of two or more metals, making it harder than the pure metal, and therefore more useful.

Question 18

What are the three states of matter?

Answer 18

Solid - fixed positions; lattice arrangement; particles vibrate when heated
Liquids - weak force of attraction; free to move past each other; don’t have definite shape; particles move in random motion always touching
Gases - very weak attraction; particles are far apart; move in random motion

Question 19

How do substances change from one state to another?

Answer 19

Solid to liquid - melting; particles have enough energy to break free from positions
Liquid to gas - boiling; particles have enough energy to break bonds

Question 20

What is the relationship of surface area and volume in nanoparticles?

Answer 20

They have a very high surface area to volume ratio.

Question 21

What are nanoparticles used for?

Answer 21

• New catalysts (large SA to V)
• Sun creams (absorbed easily by body, good skin coverage)
• In tiny electric circuits for computer chips (cam conduct electricity)
• Silver nanoparticles have antibacterial properties so are used in polymer fibres, surgical masks, and wound dressings
• Used in moisturisers without making them oily

Question 22

What is wrong with using nanoparticles?

Answer 22

We do not know the feats of nanoparticles on health because it is not yet fully understood. we do not know the long term effects