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End Of Year Science > Chemistry > Flashcards

Flashcards in Chemistry Deck (15):
1

What is valency?

The amount of electrons that an atom needs to lose or gain to have a full outer valence shell.

2

What is an indicator?

Chemical that changes colour depending on the acidity of the solution it is in.

3

What is an acid?

A compound containing hydrogen that gives free hydrogen ions in a solution.

4

What is a base?

A compound that neutralizes an acid.

5

What are ionic and covalent bonds?

Ionic- oppositely charged ions attract each other.
Covalent- atoms share electrons.

6

What is a salt?

The ionic compound formed between an acid and a base.

7

What are pure substances and impure substances?

Pure substances are elements and compounds.
Impure substances are mixtures.

8

What elements are liquids, gases and solids at room temperature?

Liquids- bromine and mercury

9

What is atomic number and mass number?

Atomic number is the number of protons and has symbol Z.
Atomic mass number is the number of nucleons and has symbol A.

10

What is the relative size of protons, neutrons and electrons?

Protons and neutrons are the same size and electrons are way smaller.

11

What are isotopes?

Isotopes are atoms of the same elements with different atomic mass numbers.

12

What is density?

The amount of mass in a given volume.

13

What is the period number equal to?

The number of shells.

14

What is the group number equal to?

The number of electrons in the outermost shell.

15

What are some highly reactive metals?

Sodium, potassium, calcium, lithium.