Elements, Compounds and Mixtures

Question 1

Define an atom and element, giving examples. (4)

Answer 1

Atoms are the building blocks of everything. (1) Hydrogen Atom (1)

An element is a substance that is made up of only one kind of atom. (1) Hydrogen (1)

Question 2

Structure of an atom and a brief description of the sub
atomic particles; protons, neutrons, and electrons. (5)

Answer 2

Atoms are made up of three smaller particles called protons + (1), electrons -(1) and neutrons o (1).
(+, - and o: represent charge)

The protons and neutrons are contained in the nucleus, the tiny centre of an atom, (1) with smaller electrons orbiting outside the nucleus (1).

Question 3

Recognise the most common elements from the periodic
table and their symbols. (6)

Answer 3

Hydrogen (1) H (1)
Helium (1) He (1)
Iron (1) Fe (1)

Question 4

Define a mixture and give examples. (4)

Answer 4

A mixture is formed when two or more elements or compounds are present without being chemically bonded together. (1)

Peas + Sweetcorn (1)
Mixture of Sweets (1)
Mixture of Coins (1)

Question 5

Distinguish between a solute, solvent and solution. (3)

Answer 5

A solution is made when a substance dissolves into a liquid. (1) The liquid is called the solvent. (1) The substance that has been dissolved is called the solute. (1)

Question 6

Describe how to separate mixtures using filtration.

Answer 6

You can separate mixtures using filtration by pouring the mixture through filter paper using a funnel.

Question 7

Describe how to separate mixtures using evaporation.

Answer 7

You can separate mixtures using evaporation by using an evaporating dish to heat the mixture until there is no liquid.

Question 8

Describe how to separate mixtures using simple distillation.

Answer 8

You can separate mixtures using distillation by heating the liquid until it cools and condenses and leaves the solid; this process is good for separating water from ink.

Question 9

Describe how to separate mixtures using fractional distillation.

Answer 9

You can separate mixtures using fractional distillation, which is used for separating mixed liquids, by boiling the liquid at different temperatures near to each of their boiling points.

Question 10

Define a compound and give examples of common
compounds.

Answer 10

Compounds formed when different atoms join; They contain two or more elements joined up. Examples of compounds are CO2 or FeS.

Question 11

Does a chemical reaction must occur for a compound to occur? (1)

Answer 11

Yes. (1)

Question 12

Define a chemical change and give examples of chemical
changes. (3)

Answer 12

A chemical change is a change of materials into another, new material with different properties and one or more new substances are formed. (1)

Wood Burning. (1)
Iron becomes rust. (1)

Question 13

List some ways you can observe a chemical reaction has
taken place. (3)

Answer 13

Bubbles (1)
Colour/Temperature Change (1)
A Large Energy Change (1)

Question 14

How to write a word equation and what a reactant and a
product are. (4)

Answer 14

A word equation represents a chemical reaction using the names of the substances involved. Word equations do not show any chemical symbols or formulae. (1) The reactants are on the left of the chemical equation, and the products on the right. (1)

In a chemical reaction, reactants are the substances that react together, and products are the substances formed. (1)

Question 15

How to name compounds, ‘ide’ and ‘ate’?

Answer 15

When two different elements combine the ending is usually, “something – ide”. When three or more elements combine - and one of them is oxygen - the ending will usually be “something – ate”. However, if two identical elements combine, it’s not a compound and their name doesn’t change.