1- Atomic structure

Question 1

Define atomic number.

Answer 1

The number of protons in its nucleus (proton number).

Question 2

Define mass number.

Answer 2

The sum of the number of protons and neutrons.

Question 3

Define relative isotopic mass

Answer 3

The mass of one atom of an isotope relative to 1/12 the mass of an atom of the isotope carbon-12.

Question 4

Define relative atomic mass, Ar.

Answer 4

The average mass of an atom of an element relative to 1/12 of the mass of an atom of the isotope carbon-12.

Question 5

Define relative molecular mass.

Answer 5

The sum of the relative atomic masses of all the atoms in its molecular formula.

Question 6

Define the first ionisation energy.

Answer 6

The energy needed to remove the first electron from each atom in one mole of gaseous atoms.

Question 7

What is shielding?

Answer 7

The effect where inner electrons reduce the pull of the nucleus on electrons in the outer shell of an atom.

Question 8

How many electrons can be held in each of the first 4 shells?

Answer 8

1: 2
2: 8
3: 18
4: 32

Question 9

Do the electrons around nuclei get closer or further in energy as you get further away?

Answer 9

Closer.

Question 10

State the order that orbitals fill in the 4th period.

Answer 10

4s, 3d, 4p