GCSE Year 10 AP4

Question 1

Compounds definition

Answer 1

When two or more different elements chemically react together. Not easily separated and the properties are completely different to the original elements.

Question 2

Element definition

Answer 2

Made up of one type of atom.

Question 3

Mixture definition

Answer 3

When two or more different elements are mixed together - easily separated and properties are a mixture of the different elements.

Question 4

Isotopes definition

Answer 4

Different atomic forms of the same element e.g. Iron II and Iron III

Question 5

What are the different subatomic particles?

Answer 5

Electrons - found in the shells, mass: 0, charge: -1
Protons - found in the nucleus, mass: 1, charge: +1
Neutrons - found in the nucleus, mass: 1, charge 0

Question 6

What are the vertical columns of the periodic table?

Answer 6

Groups - shows the number of electrons in the outer shell, so elements in the same group have similar properties

Question 7

What are the horizontal columns of the periodic table?

Answer 7

Periods - show the number of shells

Question 8

What is the electron arrangement in the shells?

Answer 8

2, 8, 8

Question 9

What are the different parts and how do you work out the number of neutrons, protons, and electrons from atoms in the periodic table?

Answer 9

12
C
6

12 represents the mass number, mass number - atomic number = number of neutrons
6 represents the atomic number, it is the number of protons and electrons

Question 10

What is an ionic bond and what properties does it have?

Answer 10

Between a non-metal and metal. Giant ionic structures which form a regular lattice arrangement.
High melting and boiling point - very strong electromagnetic forces between the ions which are hard to break.
Conducts electricity when it’s dissolved in a solution - the ions separate and the electrons are free to move so they carry the current.

Question 11

What is a simple covalent bond and what are its properties?

Answer 11

Between a two non-metals. Involves sharing of electrons.
Low melting and boiling points - weak intermolecular forces which are easy to break.
Don’t conduct electricity - no free electrons to carry the charge.

Question 12

What is a giant covalent bond and what are its properties?

Answer 12

Very high melting points - lots of strong covalent bonds to be broken.
Graphite does conduct electricity - free electrons.

Question 13

What are the properties of metallic bonds?

Answer 13

High melting and boiling points - strong bonds
Good conductors of electricity - free electrons
Malleable and ductile - free electrons allow atoms to slide over each other

Question 14

Atoms definition

Answer 14

Atoms make up everything.

Question 15

Shape memory alloys definition

Answer 15

Alloy which can deform and return to its original shape e.g. Frames for glasses.

Question 16

Nanoparticle definition

Answer 16

A very small particle/structure between 1 and 100nm in size.

Question 17

Polymer definition

Answer 17

Monomer must have a double bond.

This double bond breaks and the monomers join together to form very long chains - polymers.

Question 18

What is low density poly(ethene)?

Answer 18

Made with a high temperature of about 200 degrees & high pressure.
Form branched chains which cannot stack together easily.

Question 19

What is high density poly(ethene)?

Answer 19

Made with a low temperature of about 60 degrees, low pressure and a catalyst.
Forms straight chains which can stack together easily.

Question 20

What is a thermosoftening polymer?

Answer 20

A polymer which softens when heated.

It has a low melting point.

Question 21

What is a thermosetting polymer?

Answer 21

A polymer which is set once made.

It has a high melting point.

Question 22

How do you do mole calculations?

Answer 22

Work out the number of moles of what you have a mass of: no. of moles = mass / Mr
Then work out the ratio.
Then work out the mass you need: mass = no. of moles x Mr

Question 23

How do you work out the yield?

Answer 23

% yield = (actual mass/theoretical mass) x 100

Question 24

How do you increase the rate of reaction?

Answer 24

Increase the…
Temperature
Concentration
Surface area

Or add a catalyst

Question 25

How can you measure the rate of reaction?

Answer 25

Precipitation
Change in mass
The volume of gas given off

Rate of reaction = amount of product formed / time

Question 26

How can you achieve more collisions to increase the rate of reaction?

Answer 26

Higher temperature - particles move faster
Higher concentration - more reactant, so collisions between important particles are more likely
Larger surface area - the particles around the surface will have more area to work on, so there will be more useful collisions
Catalyst increases the number of successful collisions - lower the activation energy

Question 27

How can you achieve faster collisions to increase the rate of reaction?

Answer 27

Increase the temperature - particles have more energy

Question 28

What is a catalyst?

Answer 28

A substance which changes the speed of a reaction without being changed or used up.

Question 29

What is an exothermic reaction?

Answer 29

A reaction which gives out energy to the surroundings, usually in the form of heat and usually shown by a rise in temperature.

Question 30

What is an endothermic reaction?

Answer 30

A reaction which takes in energy from the surroundings, usually in the form of heat showing a fall in temperature.

Question 31

What is a reversible reaction?

Answer 31

A reaction where the products of the reaction can themselves react to produce the original reactants.

Question 32

What is an acid?

Answer 32

A substance with a pH of less than 7. Form H+ ions in water.

Question 33

What is a base?

Answer 33

A substance with a pH of greater than 7.

Question 34

What is an alkali?

Answer 34

A base that dissolves in water to form OH- ions.

Question 35

acid + base ->

H+ + OH- ->

Answer 35

salt + water

H2O