Revision Y7

Question 1

What is a atom?

Answer 1

The smallest part of a chemical element that can exist.

Question 2

What is a compound?

Answer 2

It is a substance made up of atoms of two or more substances.

Question 3

What is a element?

Answer 3

It is an substance that cannot be broken down into other substances.

Question 4

What is a period?

Answer 4

A row of chemical elements in the Periodic Table.

Question 5

What is a chemical change?

Answer 5

A change that makes new chemical substances.

Question 6

What is oxidation?

Answer 6

A reaction where oxygen is added to a substance.

Question 7

What element has one carbon atom and two oxygen atoms?

Answer 7

Carbon Dioxide.

Question 8

Physical change?

Answer 8

A reversible change such as melting or boiling.

Eg.Water

Question 9

What atoms are in carbon dioxide?

Answer 9

One carbon atom and two Oxygen atoms.

Question 10

Name 5 elements in the Periodic Table.

Answer 10

Copper,Carbon ,Calcium, Aluminium and Chlorine.

Question 11

What is the meaning of Combustion?

Answer 11

When fuels burn in chemical reactions.

Question 12

What is the meaning of endothermic?

Answer 12

It is when a substance has turned cold.

Question 13

What does exothermic mean?

Answer 13

When a substance has turned hot.

Question 14

What is the reactant and product of Carbon Dioxide?

Answer 14

Carbon + Oxygen = Carbon dioxide

Reactant+Reactant = Product

Question 15

What is a chemical reaction?

Answer 15

It is a change in which atoms are rearranged to create new substances.

Question 16

How would you know if a solution is concentrated?

Answer 16

It will have more acids in it.

Question 17

What does corrosive mean?

Answer 17

It will mean that it may burn skin and eyes.

Question 18

An acid has a PH of…

Answer 18

less than 7.

Question 19

An alkali has a PH of…

Answer 19

more than 7.

Question 20

What PH would it be if it was neutral?

Answer 20

Exactly 7.

Question 21

What is an universal indicator?

Answer 21

It is a mixture of dyes. It changes colour to show how acidic or alkaline it is.

Question 22

Name three types of acids.

Answer 22

Lemon juice, Vinegar and Coke.

Question 23

Name three types of alkaline.

Answer 23

Toothpaste, drain cleaner and milk of magnesia.

Question 24

How do you know if it is a chemical reaction?

Answer 24

If it has foul stink or sweet smell, has sparks or big fire, if you hear a pop or fizz and if you feel it getting hotter or colder.

Question 25

When handling something corrosive what protective kit should you wear?

Answer 25

Wear safety googles to avoid eyes from burning.

Question 26

What is a base?

Answer 26

A base is a substance that neutralises acids.

Question 27

What happens in a neutralisation reaction?

Answer 27

In a neutralisation reaction an acid reacts with a substance that cancels it out. The PH gets closer to 7.

Question 28

What does decomposition reaction?

Answer 28

A decomposition reaction is a type of chemical reaction in which a single compound breaks down into two or more elements or new compounds.