C3 - 1, 2, 3

Question 1

What are elements?

Answer 1

Elements are substances made of atoms that all contain the same number of protons and cannot be spilt into anything simpler.
-118 elements in Periodic Table.

Question 2

What are compounds?

Answer 2

Compounds are pure substances made up of two or more elements chemical combined. There is an unlimited number of compounds.
Compounds cannot be separated into their elements by physical means.
E.g. CaCO3

Question 3

What is a mixture?

Answer 3

A mixture is a combination of two or more substances (elements and/or compounds) that are NOT chemically combined.

Question 4

Can mixtures by separated by physical methods?

Answer 4

Yes, mixtures can be separated by physical methods such as filtration or evaporation.
E.g. sand and water.

Question 5

What are metals?

Answer 5

Metals are solid materials that can conduct heat and electricity and are malleable.
-Left side of period table.

Question 6

What are non metals?

Answer 6

Non metals can be any state and do NOT conduct electricity electricity or heat (except for graphite).

Question 7

What is a solvent?

Answer 7

A solvent is a substance that is able to dissolve other substances.
E.g. water.

Question 8

What is a solute?

Answer 8

A solute is a substance that is dissolved in a solution by a solvent.

Question 9

What is a solution?

Answer 9

A solution is a homogenous mixture of one or more solutes dissolved in a solvent.

Question 10

What is concentration?

Answer 10

Concentration is a measure of the amount of a substance that a solution contains.

Question 10

What are all substances made up of?

Answer 10

All substances are made up atoms which are the building blocks of all matter.

Question 11

What is an atom made up of?

Answer 11

An atom is made up of subatomic particles known as protons, neutrons and electrons.

Question 12

What does the nucleus contain?

Answer 12

The nucleus contains the protons and neutrons.

Question 12

What is located at the centre of an atom?

Answer 12

At the centre of an atom, is the nucleus.

Question 13

Where are the electrons in an atom?

Answer 13

The electrons orbit the nucleus in orbital paths called shells.

Question 14

What is meant by the build up of electrons in shells?

Answer 14

The first shell is nearest to the nucleus and can only contain two electrons. All of the following shells can hold 8 electrons.

Question 15

What is an electronic configuration?

Answer 15

An electronic configuration is the arrangement of the electrons in shells.

Question 16

What are valence electrons?

Answer 16

Valence electrons are the number of electrons in an atom’s outer shell.

Question 17

Why are valence electrons important?

Answer 17

Valence electrons are important as they determine whether a reaction will take place and if yes, what products will be formed.

Question 18

Why are noble gases electronic configuration significant?

Answer 18

Thus, this is either 2 or 8 meaning they have full outer shells of electrons. They have a stable electronic structure meaning they are very unreactive and cannot lose or gain electrons to take part in chemical reactions (no need).

Question 19

What are the charges of the subatomic particles?

Answer 19

Protons = +1
Neutrons = 0
Electrons = -1

Question 20

What are the relative masses of the subatomic particles?

Answer 20

Protons = 1
Neutrons = 1
Electrons = Negligible. 1 divided by 1840

Question 21

What is the proton number? - atomic number

Answer 21

Proton number is the number of protons in the nucleus of an atom. - Small number of an element.

Question 22

What is the nucleon number? - atomic mass number

Answer 22

The nucleon number is the total number of protons and neutrons in the nucleus of an atom. - Large number of an element.

Question 23

Why does an atom have the same amount of electrons as protons?

Answer 23

An atom has the same number of electrons as protons because it is neutral - and they have to cancel out.

Question 24

What does the period of an element show?

Answer 24

The period of an element (horizontal) shows the number of notations an atom has.
E.g. Cl is in period 3 and has 3 notations in its electronic structure.
2,8,7

Question 25

What does the group of an element show?

Answer 25

The group of an element shows the number of electrons it has in its outer shell.
E.g. Cl is in group 7 and has 7 electrons on its outer shell.
-Elements in the same group have the same number of outer shell electrons.

Question 26

What are isotopes?

Answer 26

Isotopes are atoms of the same element which have the same proton number but a different nucleon number.

Question 27

Why do isotopes have the same properties?

Answer 27

because they have the same number of electrons in their outer shell.

Question 28

What are physical changes?

Answer 28

In physical changes, no new substances are produced. The substance undergoing change may have a different shape or state but is the same substance at the end.
e.g. boiling water, melting ice, breaking a bottle, crumbling paper.

Question 29

What are chemical changes?

Answer 29

Chemical changes produce a new substance and either absorb or release heat during this process.
e.g. burning wood, digesting food.

Question 30

What are reversible reactions?

Answer 30

Reversible reactions are that in some chemical reactions, the products of the reaction can react to produce the original reactants.

Question 31

How can the direction of the reaction in a reversible reaction be changed?

Answer 31

They can be changed by changing the conditions.

Question 32

What is the reaction between anhydrous copper sulphate and water?

Answer 32

-Anhydrous​ ​copper(II)​ ​sulfate​ ​+​ ​water​ ​⇌​ ​hydrated​ ​copper(II)​ ​sulfate
-White​ ​solid​ ​turns​ ​blue​ ​in​ ​presence​ ​of​ ​water
-For a forward reaction, add water.

Question 33

How to reverse the reaction between anhydrous copper sulfate and water?

Answer 33

-Anhydrous​ ​copper(II)​ ​sulfate​ ​+​ ​water​ ​⇌​ ​hydrated​ ​copper(II)​ ​sulfate
-Reverse the reaction by heating the hydrated copper sulfate so that the water evaporates.