chemical changes and structure - periodicity, structure and bonding, Oxidising and reducing agents

Question 1

Atomic Number

Answer 1

The number of protons in the nucleus of an atom, which determines the element’s position in the periodic table.

Question 2

Groups (Periodic Table)

Answer 2

Vertical columns in the periodic table that contain elements with similar chemical properties due to having the same number of electrons in their outer shell.

Question 3

Periods (Periodic Table)

Answer 3

Horizontal rows in the periodic table where elements are arranged in order of increasing atomic number, showing a progression from metallic to non-metallic properties.

Question 4

Metallic Bonding

Answer 4

A type of bonding that occurs in metals, where electrons are shared among a lattice of atoms.

Question 5

Covalent Molecular Substances

Answer 5

Substances made up of molecules with covalent bonds, where atoms share electrons (e.g., H₂, O₂, P₄).

Question 6

Covalent Network Substances

Answer 6

Substances where atoms are bonded covalently in a continuous network extending throughout the material (e.g., diamond, graphite).

Question 7

Monatomic Elements

Answer 7

Elements that consist of single atoms not bonded to each other (e.g., noble gases like He, Ne).

Question 8

Covalent Radius

Answer 8

A measure of the size of an atom that forms part of a single covalent bond.

Question 9

First Ionisation Energy

Answer 9

The energy required to remove one mole of electrons from one mole of gaseous atoms to form ions.

Question 10

Second Ionisation Energy

Answer 10

The energy required to remove an additional mole of electrons after the first has been removed.

Question 11

Electronegativity

Answer 11

A measure of an atom’s ability to attract and hold onto electrons in a chemical bond.

Question 12

Covalent Bond

Answer 12

A type of chemical bond where atoms share pairs of electrons.

Question 13

Polar Covalent Bond

Answer 13

A covalent bond in which electrons are shared unequally, resulting in a dipole (partial charges δ+ and δ-).

Question 14

Ionic Bond

Answer 14

A chemical bond formed through the electrostatic attraction between positively and negatively charged ions.

Question 15

Bonding Continuum

Answer 15

The range of bonding from purely covalent to purely ionic, with polar covalent bonding in between.

Question 16

Intermolecular Forces

Answer 16

Forces of attraction or repulsion between molecules, including van der Waals forces.

Question 17

London Dispersion Forces

Answer 17

Weak intermolecular forces arising from temporary dipoles induced by electron movement.

Question 18

Permanent Dipole-Permanent Dipole Interactions

Answer 18

Attractive forces between molecules with permanent dipoles due to polar bonds.

Question 19

Hydrogen Bonding

Answer 19

A strong type of dipole-dipole interaction occurring when hydrogen is bonded to a highly electronegative atom (F, O, N).

Question 20

Oxidation

Answer 20

A chemical process where a substance loses electrons.

Question 21

Reduction

Answer 21

A chemical process where a substance gains electrons.

Question 22

Redox Reaction

Answer 22

A reaction in which both reduction and oxidation occur simultaneously.

Question 23

Oxidising Agent

Answer 23

A substance that accepts electrons in a redox reaction, causing another substance to be oxidised.

Question 24

Reducing Agent

Answer 24

A substance that donates electrons in a redox reaction, causing another substance to be reduced.

Question 25

Electrochemical Series

Answer 25

A series of reduction reactions arranged in order of increasing reduction potential, indicating the strength of oxidising and reducing agents.

Question 26

Ion-Electron Equation

Answer 26

A balanced chemical equation that includes ions and electrons to represent redox reactions.

Question 27

Solubility

Answer 27

The ability of a substance to dissolve in a solvent, which depends on the nature of the solute and solvent and their intermolecular forces.

Question 28

Van der Waals Forces

Answer 28

Weak intermolecular forces that include London dispersion forces and dipole interactions.