3 groups spaced apart, each containing 2 touching grey circles

2 groups spaced apart, each containing 3 touching circles, one of which is white, one of which is black and one of which is grey

9 grey circles all touching, arranged in a 3 by 3 square

All diagrams show an element, except one. Which does not show an element?

A substance that has two or more different elements chemically bonded together is a {{}}.

Elements are determined by the number of {{}} in the nucleus.

The name of the compound that contains one potassium atom, one carbon atom and three oxygen atoms is {{}}.

KCO3 (with the 3 as a standard case number)

The formula for the compound that contains one potassium atom, one carbon atom and three oxygen atoms is ...

Key stage 4

Atoms, elements and compounds

two or more different elements chemically bonded together

All 118 known elements are displayed in the {{}}.

Calcium is added to hydochloric acid to produce calcium chloride and hydrogen. What are the **two** reactants?

Iron oxide breaks down into iron and oxygen. What are the **two** products?