Atomic Structure Revision

The centre of an atom is called the nucleus.

• True

• False

The positively charged particles in the nucleus (centre) of an atom are called...

• Decepticons

• Electrons

• Protons

• Neutrons

The particles in atoms (protons, neutrons and electrons) are weighed in 'amu'. What does 'amu' stand for?

• Australian Macintosh Users

• Atomic Mass Units

• Andy's Maddening Ulcer

• Atomic Mega Ultras

The negatively charged particles that orbit the nucleus of an atom are called...

• Electrons

• Protons

• Neutrons

• Neutrinos

The mass number of an atom is equal to...

• Protons + Electrons

• Electrons + Neutrons

• Neutrons + Neutrons

• Protons + Neutrons

What is the mass number of this Carbon atom?

• 12

• 6

• C

Answer explanation

Mass number is always at the top of the chemical symbol.

What is the atomic number of this Carbon atom?

• 12

• 6

• C

Answer explanation

Atomic number is always at the bottom of the chemical symbol.

How many protons does this Carbon atom have?

• 12

• 6

• C

Answer explanation

Atomic number = number of protons.

How many neutrons does this Carbon atom have?

• 12

• 6

• 18

Answer explanation

Mass number = protons + neutrons, therefore:

Number of neutrons = mass number - atomic number, so:

Number of neutrons = 12 - 6 = 6

Using this table, calculate the correct electron configuration for Flourine, which has atomic number 9 and therefore 9 electrons.

• 2,7

• 2,5,2

• 2,9

• 9