Atomic Structure

Question 1

What is the definition of a proton?

Answer 1

A nucleic particle with a positive charge

Question 2

What is the definition of an electron?

Answer 2

A subatomic particle with a negative charge

Question 3

What is the definition of a neutron?

Answer 3

A nucleic particle with no charge

Question 4

What is a mass number?

Answer 4

The total number of protons AND neutrons in a nucleu

Question 5

What is an atomic number?

Answer 5

The number of protons in a nucleus

Question 6

Where is the K-shell located, and how many electrons can it hold?

Answer 6

It’s the orbital nearest the nucleus and can house 2 electrons

Question 7

Where is the L-shell located, and how many electrons can it hold?

Answer 7

It’s the orbital second farthest from the nucleus and can house 8 electrons

Question 8

What is a nuclide?

Answer 8

A nuclide is a species of atom defined by its nuclear makeup i.e. its mass number (A) and atomic number (Z)

Question 9

What is an isotope (of an element)?

Answer 9

An isotope is a variation of an element, that has the same atomic number (Z) as the given element, but a different mass number (A).

Same number of protons, differing number of neutrons

Question 10

What is a radionuclide?

Answer 10

A radionuclide is an atom whose atomic (Z) and mass (A) number (i.e. its nucleus) make it unstable and emit radiation in order to stablise itself.

Question 11

What is the symbol for atomic number?

Answer 11

Z

Question 12

What is the symbol for mass number?

Answer 12

A

Question 13

What is an element?

Answer 13

A nucleus with a given value of Z (i.e. a specified number of protons).

Question 14

What is a radioisotope?

Answer 14

A radioisotope of an element is an isotope whose nuclear makeup make it unstable and emit radiation in an attempt to stablise itself.

Question 15

How does an orbital’s distance from the nucleus affect the binding energy of electrons housed in it?

Answer 15

The farther from the nucleus, the lower its binding energy

Question 16

How does an orbital’s distance from the nucleus affect the potential energy of electrons housed in it?

Answer 16

Farther from the nucleus, the higher its potential energy

Question 17

How does atomic number affect binding energy?

Answer 17

The atomic number (Z) corresponds to the number of protons. Therefore, a higher number of protons means a greater electrostatic force between protons and electrons in the atom, increasing the binding energy (especially in orbitals closer to the nucleus).

Question 18

Describe the electron configuration of carbon

Answer 18

Atomic number (Z) is 6, so:
K-shell = 2 electrons
L-shell = 4 electrons

Question 19

Describe the electron configuration of chlorine

Answer 19

Atomic number (Z) is 17, so:
K-shell = 2
L-shell = 8
M-shell = 7

Question 20

How do binding energies relate to the energies of x-ray photons produced?

Answer 20

X-ray photons produced via characteristic radiation have an energy equal to the difference in binding energies of the ejected electron and the electron that ‘falls down’ to replace it.

Question 21

How are electrons organised in the Bohr model of an atom?

Answer 21

Contained within shells which form concentric circles around the nucleus