Chemistry

What is the charge of an electron?

-1

What is the charge of a proton?

+1

What is the charge of a neutron?

0

What is the relative mass of an electron?

1/1836

What is the relative mass of a proton and neutron?

1

What does the atomic number show?

The number of protons or electrons.

What does the mass number show?

The number of protons plus neutrons.

How many electrons can the first shell hold?

2

How many electrons can the second and third hold?

8

What does the group on the periodic table show?

The number of electrons in the outer shell.

What does the period on the periodic table show?

The number of shells.

Why are noble gases unreactive?

They have a full outer shell.

What is an ion?

An atom with an electrical charge.

True or False: An ion drawing has square brackets.

True

What is a positive ion called?

A cation.

What is a negative ion called?

An anion.

What is the charge of an ion in group 1?

1+

What is the charge of an ion in group 2?

2+

What is the charge of an ion in group 3?

3+

what is the charge of an ion in group 5?

3-

What is the charge of an ion in group 6?

2-

What is the charge of an ion in group 7?

1-

What Is a complex ion?

An ion made of a group of atoms.

What charges do ions need to have to make a neutral compound?

Opposite.

How can we work out how many of each ion needs to join together?

Using the charge of ions.

What is an acid?

A substance that releases hydrogen ions in water.

Give three common laboratory acids.

Hydrochloric acid, sulfuric acid, nitric acid.

What do acid taste like?

Sour

What gas is produced when acids react with metals?

Hydrogen gas.

What gas is produced when acids react with carbonates?

Carbon dioxide.

What colour does blue litmus paper turn in acids?

Red.

What pH values do acids have?

Less than 7.

What is a base?

A substance that neutralises an acid.

What is an alkali?

A soluble base that releases OH ions in water.

What does the pH scale measure?

How acidic or alkaline a substance is.

What is the pH of a neutral substance?

7.

What pH range is a strong acid?

0-3.

What pH range is a weak/slightly acidic substance?

4-6.

What pH range is a weak/slightly alkaline substance?

8-10

What pH range is a strong alkaline substance?

11-14

What colour is universal indicator in a strong acid?

Red.

What colour is universal indicator in a weak acid?

Orange/yellow.

What colour is universal indicator at neutral pH?

Green.

What colour is universal indicator in a weak alkali?

Blue.

What colour is universal indicator in a strong alkali?

Purple.

What colour does red litmus turn in alkali?

Blue.

What colour does blue litmus turn in acid?

Red.

What colour is phenolphthalein in acid?

Colourless.

What colour is phenolphthalein in alkali?

Pink.

What colour is methyl orange in acid?

Red.

What colour is methyl orange in alkali?

Yellow.

What is neutralisation?

A reaction between an acid and a base.

What are the products of acid + alkali?

Salt + water.