C1: Glossary

Question 1

What is a aqueous solution ?

Answer 1

The mixture made by adding a soluble substance to water

Question 2

What is an atom ?

Answer 2

The smallest part of an element that can still be recognised as that element.

Question 3

What is an atomic number ?

Answer 3

The number of protons (which equals the number of electrons) in an atom. It is sometimes called the proton number.

Question 4

What is a balanced symbol equation ?

Answer 4

A symbol equation in which there are equal numbers of each type of atom on either side of the equation.

Question 5

What is a biofuel ?

Answer 5

Fuel made from animal or plant products.

Question 6

What is chromatography ?

Answer 6

The process whereby small amounts of dissolved substances are separated by running a solvent
along a material such as absorbent paper.

Question 7

What is a compound ?

Answer 7

A substance made when two or more elements are chemically bonded together

Question 8

What is an electron ?

Answer 8

a tiny particle with a negative charge. Electrons orbit the nucleus of atoms or ions in shells

Question 9

What is electronic structure ?

Answer 9

A set of numbers to show the arrangement of electrons in their shells (or energy levels)

Question 10

What is an element ?

Answer 10

A substance made up of only one type of atom. An element cannot be broken down chemically into any
simpler substance

Question 11

What is a group ?

Answer 11

All the elements in the columns (labelled 1 to 7 and 0) in the periodic table

Question 12

What is an ion ?

Answer 12

A charged particle produced by the loss or gain of electrons

Question 13

What is an isotope ?

Answer 13

Atoms that have the same number of protons but different number of neutrons, i.e., they have the same atomic
number but different mass numbers

Question 14

What is the law of conservation of mass ?

Answer 14

The total mass of the products formed in a reaction is equal to the total mass of the reactants

Question 15

What is mass number ?

Answer 15

The number of protons plus neutrons in the nucleus of an atom

Question 16

What is a neutron ?

Answer 16

A dense particle found in the nucleus of an atom. It is electrically neutral, carrying no charge

Question 17

What are noble gases

Answer 17

The very unreactive gases found in Group 0 of the periodic table. Their atoms have very stable electronic structures

Question 18

What is a nucleus (of an atom) ?

Answer 18

The very small and dense central part of an atom that contains protons and neutrons

Question 19

What is the periodic table ?

Answer 19

An arrangement of elements in the order of their atomic numbers, forming groups and periods

Question 20

What is a product ?

Answer 20

A substance made as a result of a chemical reaction

Question 21

What is a proton ?

Answer 21

A tiny positive particle found inside the nucleus of an atom

Question 22

What is a reactant ?

Answer 22

A substance we start with before a chemical reaction takes place

Question 23

What is a shell in atomic structure ?

Answer 23

An area in an atom, around its nucleus, where electrons are found

Question 24

What is a state symbol ?

Answer 24

The abbreviations used in balanced symbol equations to show if reactants and products are solid (s), liquid (l), gas
(g) or dissolved in water (aq)

Question 25

What is a symbol equation ?

Answer 25

An equation that helps you see how much of each substance is involved in a chemical reaction by showing the
chemical symbols and formulae of all the reactants and products involved

Question 26

What is a word equation ?

Answer 26

A way of describing what happens in a chemical reaction by showing the names of all reactants and the products
they form