Key Words!💢💢💢

the mixture made by adding a soluble substance to water

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

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

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

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

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

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

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

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

a charged particle produced by the loss or gain of electrons

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

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

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

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

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

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

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

a substance made as a result of a chemical reaction

a tiny positive particle found inside the nucleus of an atom

a substance we start with before a chemical reaction takes place

an area in an atom, around its nucleus, where electrons are found that holds electrons. The further the electrons are, the less attracted they are to the nucleus (protons).

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)

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

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