Particles and Mixtures - 1.4 Atoms

Name the particles that are found in the nucleus of an atom

protons and neutrons

What is the charge of a proton?

Positive 1 or +1 (You can remember p for proton and p for positive)

What is the charge of a neutron?

Neutral of 0 (You is as neutr is the first 5 letters in both neutron and neutral)

What is the charge of an electron?

Negative 1, or -1

What is the relative mass of a proton

1

What is the relative mass of a neutron?

1

What is the relative mass of an electron?

In exams you can say 0, 1/2000, or "negligible".

What is the overall charge of an atom?

Neutral or 0. If an atom does have a positive or negative charge - it's not an atom, its an "ion")

Why do atoms have a neutral charge?

Because they have the same number of positive protons and negative electrons, so the charges cancel out.

Why does the "atomic number" of an atom tell you?

The number of protons the atom has. It also tells you the number of electrons it has but only if it is a neutral atom - if the atom has a charge, it;s an ion, and the atomic number won't tell you the number of electrons.

What does the mass number of an atom tell you?

The total number of protons + neutrons the atom has.

How can you use the atomic number and mass number of a given atom, to work out how many neutrons it has?

Number of neutrons = mass number - atomic number

What are the given numbers indicated by A and B?

A - Mass number B - Atomic number