Periodic Table

acid rain

Rain that has a non-metal dissolved in it.

chemical property

How a substance behaves in its chemical reactions.

density

The mass of a material in a certain volume.

displace

A more reactive metal displaces – or pushes out – a less reactive metal from its compound.

displacement reaction

In a displacement reaction, a more reactive metal displaces – or pushes out – a less reactive metal from its compound.

group

A vertical column of the Periodic Table. The elements in a group have similar properties.

Group 0

Group 0 is on the right of the Periodic Table. Group 0 elements include helium, neon, argon, and krypton.

Group 1

The elements in the left column of the Periodic Table, including lithium, sodium, and potassium.

Group 7

Group 7 is the second from the right of the Periodic Table. Group 7 elements include fluorine, chlorine, bromine, and iodine.

halogen

Another name for the Group 7 elements.

metal

Elements on the left of the stepped line of the Periodic Table. Most elements are metals. They are good conductors of energy and electricity.

metalloid

Elements near the stepped line of the Periodic Table are metalloids.

noble gases

Another name for the Group 0 elements.

non-metal

Elements on the right of the stepped line of the Periodic Table. They are poor conductors of energy and electricity.

period

A horizontal row of the Periodic Table. There are trends in the properties of the elements across a period.

physical property

A property of a material that you can observe or measure.

reactive

A substance is reactive if it reacts vigorously with substances such as dilute acids and water.

unreactive

Elements that take part in few chemical reactions are unreactive.