Chemistry

Question 1

What is a molecule?

Answer 1

The general name for a combination of multiple atoms, this can be an element or a compound.

Question 2

What is a mixture?

Answer 2

2 or more substances that are combined but not chemically bound together.

Question 3

What is a compound?

Answer 3

A compound is a combination of 2 or more substances that are chemically bound together.

Question 4

What is distillation?

Answer 4

The action of purifying a liquid by a process of heating and cooling

Question 5

What is crystallisation?

Answer 5

When a product is made as a solution, one way to separate it from the solvent is to make crystals. This involves evaporating the solution to a much smaller volume and then leaving it to cool. As the solution cools, crystals form, and these can be obtained by filtration.

Question 6

What is filtration?

Answer 6

This technique is used to separate an insoluble solid from a liquid. It can be used to obtain a product that is free from unreacted chemicals, by-products or solvent.

Question 7

What do all the atoms of a particular element have in common?

Answer 7

They all have the same number of protons?

Question 8

What is the relative charge of:
Protons
Neutrons
Electrons

Answer 8

Proton: +1
Neutron: 0
Electron: -1

Question 9

What is plum pudding?

Answer 9

The plum pudding model was simply an atom full of ‘positive jelly’ with negative electrons floating around in it.

Question 10

What do electrons determine and why?

Answer 10

They determine an atom’s chemical properties as they are the parts that touch other atoms as they are on the outside.

Question 11

Lithium, Sodium and Potassium all have one electron in their outer shell, suggest whether they will react similarly or differently in water and explain why,

Answer 11

They are similar chemically and are in the same group on the Periodic Table so will react similarly.

Question 12

What are isotopes?

Answer 12

Atoms of the same element with a different number of neutrons but the same number of protons.

Question 13

What is an ion?

Answer 13

An ion is an atom that has lost or gained electrons so it is charged. It usually does this to get a noble gas configuration.

Question 14

What is mass number?

Answer 14

Mass number is the amount of protons + neutrons in the nucleus of an atom. Atomic number is the number of protons in each atom of an element.

Question 15

Name the sub-atomic particles found in the nucleus of an atom.

Answer 15

Protons and Neutrons

Question 16

What is the maximum number of electrons that can occupy each of the first two energy levels (or shells)?

Answer 16

8

Question 17

Explain the overall charge of any atom

Answer 17

The overall charge of any atom is neutral

Question 18

How can an atom become an ion with a 2+ charge?

Answer 18

An atom can gain 2 electrons from another atom and become an ion.

Question 19

What is atomic number?

Answer 19

Atomic number is the number of protons in each atom of an element

Question 20

What is an element?

Answer 20

It is a substance made up of one type of atom that is found in the Periodic Table

Question 21

How would you separate salt and water?

Answer 21

You would evaporate the mixture by heating it to it’s boiling point and turning a liquid into a gas.

Question 22

What is condensation?

Answer 22

A gas turning into a liquid by decreasing the temperature

Question 23

What are melting point and boiling point?

Answer 23

Melting point is the temperature at which a solid turns to a liquid.
Boiling point is the temperature at which a liquid turns into a gas.

Question 24

What is chromatography?

Answer 24

The process of separating substances according to solubility and condensity

Question 25

What is a solute?

Answer 25

The solid that can be dissolved into a solvent

Question 26

What is a solvent?

Answer 26

The liquid that will help dissolve the solute

Question 27

What is a solution?

Answer 27

A mixture of the solute and solvent