Terms: Atomic structure

Question 1

Atomic emission spectra

Answer 1

Atomic emission spectra: The characteristic line spectrum that occurs as a result of energy being released by individual elements. Coloured lines on a black background.

Question 2

Atomic absorption spectra:

Answer 2

Atomic absorption spectra: The characteristic line spectrum that occurs as a result of energy being absorbed by individual elements. Black lines on a continuum (coloured) background.

Question 3

Atomic number

Answer 3

Atomic number: Number of protons in the nucleus.

Question 4

Mass number:

Answer 4

Mass number: Number of nucleons (protons and neutrons) in the nucleus

Question 5

Aufbau principle

Answer 5

Aufbau principle: The principle that states that lowest energy levels are filled first.

Question 6

Hund’s rule

Answer 6

Hund’s rule: Orbitals within the same sub-shell are filled singly first.

Question 7

Ionization energy, first:

Answer 7

Ionization energy, first: Energy required to remove one mole of electrons from an atom in its gaseous state.

Question 8

Isotopes

Answer 8

Isotopes: Atoms that contain the same number of protons but a different number of neutrons.

Question 9

Orbital

Answer 9

Orbital: A region of space around the nucleus of an atom that is occupied by a maximum of two electrons at any given time.

Question 10

Pauli’s exclusion principle:

Answer 10

Pauli’s exclusion principle: electrons in single orbital must have opposite spin.

Question 11

Relative abundances

Answer 11

Relative abundances: The percentage of natural occurrence of an isotope of an element.

Question 12

Relative atomic mass:

Answer 12

Relative atomic mass: The weighted mean of all the naturally occurring isotopes of the element relative to 12C. No units.

Question 13

Valence electrons:

Answer 13

Valence electrons: The electrons in the highest main energy level.