C1 Atomic structure

Question 1

aqueous solution

Answer 1

the mixture made by adding a soluble substance to water

Question 2

atom

Answer 2

the smallest part of an element that can still be recognised as that element

Question 3

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

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

biofuel

Answer 5

fuel made from animal or plant products

Question 6

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

compound

Answer 7

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

Question 8

electron

Answer 8

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

Question 9

electronic structure

Answer 9

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

Question 10

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

group

Answer 11

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

Question 12

ion

Answer 12

a charged particle produced by the loss or gain of electrons

Question 13

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

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

mass number

Answer 15

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

Question 16

neutron

Answer 16

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

Question 17

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

nucleus (of an atom)

Answer 18

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

Question 19

periodic table

Answer 19

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

Question 20

product

Answer 20

a substance made as a result of a chemical reaction

Question 21

proton

Answer 21

a tiny positive particle found inside the nucleus of an atom

Question 22

reactant

Answer 22

a substance we start with before a chemical reaction takes place

Question 23

shell

Answer 23

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

Question 24

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

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

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