Chemistry yr 8

Question 1

Chemical Formula

Answer 1

Shows the number of atoms of each element in a substance.

Question 2

Noble Gases

Answer 2

Elements with complete outer electron shells and low reactivity.

Question 3

Subscript

Answer 3

A smaller number written below the line in a chemical formula.

Question 4

Atom

Answer 4

The basic unit of an element.

Question 5

Combining Power (Valency)

Answer 5

The number of bonds an element can form to achieve stability.

Question 6

Valency Number

Answer 6

The electrons an atom needs to gain, lose, or share for a full outer electron shell.

Question 7

Group of the Periodic Table

Answer 7

Elements in the same group share the same valency.

Question 8

ion

Answer 8

a charged atom

Question 9

complex ions

Answer 9

ions with a central metal ion bonded to one or more molecules or ions

Question 10

Halogen

Answer 10

group 7 on the periodic table (fluorine, chlorine, bromine and iodine). They are non metals and are very reactive.

for example, helium, neon and argon

Question 11

element

Answer 11

a substance made up of only one type of atom

Question 12

compound

Answer 12

2 or more atoms chemically bonded together

Question 13

group 1

Answer 13

alkali metals - they are solid at room temperature and they are very reavtive