Atomic and Electronic Structure

Question 0

What are the relative charges of protons, neutrons and electrons?

Answer 0

Proton: 1+
Neutron: 0
Electron: 1-

Question 1

What are the relative masses of protons, neutrons and electrons?

Answer 1

Proton: 1
Neutron: 1
Electron: 1/2000

Question 2

What is the distribution of mass within an atom?

Answer 2

Almost all of the mass is concentrated in the nucleus, because that is where the protons and neutrons, which make up virtually all of the atom’s mass, are located.

Question 3

What is the distribution of charge within an atom?

Answer 3

The nucleus is positively charged, because it contains only protons and neutrons, and the orbitals are negatively charged, because they contain the electrons.

Question 4

What is the atomic number?

Answer 4

It is the number of protons in an atom of an element.

Question 5

What is the mass number?

Answer 5

It is the number of protons and neutrons (nucleons) in an element.

Question 6

What is an isotope?

Answer 6

An atom of an element with a different number of neutrons and therefore a different mass.

Question 7

What is an ion?

Answer 7

A positively or negatively charged atom or covalently bonded group of atoms.

Question 8

What is the first ionisation energy of an element?

Answer 8

The energy required to remove on electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions.

Question 9

What are successive ionisation energies?

Answer 9

A measure of the energy required to remove each electron in turn, i.e. for the nth ionisation energy, it is the energy required to remove one electron from each atom in one mole of gaseous (n-1)+ ions to form one mole of gaseous n+ ions.

Question 10

What are ionisation energies influenced by? Are there any incidences where one factor outweighs another?

Answer 10

Nuclear charge (which increases it), electron shielding (which decreases it), and atomic radius (which decreases it). Electron shielding outweighs nuclear charge down a group.

Question 11

How many electrons can fill the first four shells? How many electrons can fill the nth shell?

Answer 11

1st: 2
2nd: 8
3rd: 18
4th: 32
nth: 2n²

Question 12

What is an orbital?

Answer 12

A region that can hold up to two electrons, with opposite spins.

Question 13

What is the shape of an s-orbital?

Answer 13

Spherical.

Question 14

What shape is a p-orbital?

Answer 14

A three-dimensional dumb-bell shape.

Question 15

How many s-orbitals, p-orbitals, d-orbitals and f-orbitals does a shell contain?

Answer 15

1 s-orbital
3 p-orbitals
5 d-orbitals
7 f-orbitals

Question 16

How many electrons occupy s, p, d and f sub-shells?

Answer 16

2 electrons in an s-orbital
6 electrons in a p-orbital
10 electrons in a d-orbital
14 electrons in a f-orbital

Question 17

What is a shell?

Answer 17

A group of atomic orbitals with the same principal quantum number, n. Also known as a main energy level.

Question 18

What is the principal quantum number?

Answer 18

A number representing the relative overall energy of each orbital, which increases with distance from the nucleus, denoted n.

Question 19

What is a sub-shell?

Answer 19

A group of the same type of atomic orbitals (s, p, d or f) within a shell.

Question 20

What are the relative energies of s, p and d-orbitals for the shells 1, 2, 3 and the 4s and 4p-orbitals, in increasing order?

Answer 20

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p

Question 21

What is the electronic configuration?

Answer 21

The arrangement of electrons in an atom.

Question 22

What are the positions of the s, p, and d-blocks in the Periodic Table?

Answer 22

The s-block is on the left, the p-block is on the right, and the d-block is in the middle.