Unit 1-Glossary

Question 1

Bonding electrons

Answer 1

Bonding electrons

are shared pairs of electrons from both atoms forming the covalent bond.

Question 2

Covalent radius

Answer 2

is half the distance between the nuclei of two bonded atoms of an element.

Question 3

Delocalised

Answer 3

Delocalised electrons, in metallic bonding, are free from attachment to any one metal ion and are shared amongst the entire structure.

Question 4

Dipole

Answer 4

an atom or molecule in which a concentration of positive charges is separated from a concentration of negative charge.

Question 5

Electronegativity

Answer 5

A measure of the attraction that an atom involved in a bond has for the electrons of the bond.

Question 6

Fullerenes

Answer 6

are molecules of pure carbon constructed from 5- and 6-membered rings combined into hollow structures. The most stable contains 60 carbon atoms in a shape resembling a football.

Question 7

Hydrogen bonds

Answer 7

are electrostatic forces of attraction between molecules containing a hydrogen atom bonded to an atom of a strongly electronegative element such as fluorine, oxygen or nitrogen, and a highly electronegative atom on a neighbouring molecule.

Question 8

Intermolecular forces

Answer 8

are those which attract molecules together. They are weaker than chemical bonds.

Question 9

Intramolecular forces

Answer 9

are forces of attraction which exist within a molecule.

Question 10

Isoelectronic

Answer 10

means having the same arrangement of electrons. For example, the noble gas neon, a sodium ion (Na+) and a magnesium ion (Mg2+) are isoelectronic.

Question 11

London Dispersion Forces

Answer 11

are the intermolecular forces of attraction which result from the electrostatic attraction between temporary dipoles and induced dipoles caused by movement of electrons in atoms and molecules.

Question 12

Miscible

Answer 12

fluids are fluids which mix with or dissolve in each other in all proportions.

Question 13

Polar covalent bond

Answer 13

a covalent bond between atoms of different electronegativity, which results in an uneven distribution of electrons and a partial charge along the bond.

Question 14

Van der Waals’ forces

Answer 14

Is the general name given to all intermolecular attractions including London dispersion forces and hydrogen bonding.

Question 15

Viscosity

Answer 15

is the resistance to flow that is exhibited by all liquids