C1 - Atoms

Question 1

What are all substances made up of?

Answer 1

Atoms.

Question 2

What do atoms contain?

Answer 2

Subatomic particles - electrons, neutrons and protons.

Question 3

What is the nucleus?

Answer 3

• It’s the middle of the atom and continue protons and neutrons.
• It has a radius of around 1/10,000.
• It has a positive charge because of the protons (protons have a charge of 1 and neutrons have 0 - they add up to make 1).
• Almost the whole mass of the atom is concentrated in the nucleus.

Question 4

What are electrons?

Answer 4

• They have virtually no mass.
• They move around the nucleus in electron shells.
• They’re negatively charged and tiny but cover up a lot of space.
• The volume of their orbits determines the size of the atom.

Question 5

What is the relative mass and charge of each subatomic particle?

Answer 5

• Relative Mass:
  Proton: 1
  Neutrons: 1
  Electron: Very small
• Charge
  Proton: +1
  Neutron: 0
  Electron: -1

Question 6

Why do atoms have no charge overall and are neutral?

Answer 6

• Because they have the same number of protons and electrons.
• The charge on the electrons and protons cancel each other’s out.
• In an ion, the number of protons doesn’t always equal the number of protons. An ion with a charge of -2 means that it has 2 more electrons then protons.

Question 7

What does the atomic number of a nuclear symbol tell you?

Answer 7

-How many protons there are.

Question 8

What does the mass number tell you?

Answer 8

-It tells you the total number of protons and neutrons.

Question 9

How do you get the number of neutrons of a nuclear symbol?

Answer 9

-Subtract the atomic number from the mass number.