Bonding

Question 1

covalent bond

Answer 1

A covalent bond is the electrostatic attraction between two nuclei and a shared pair of electrons

Question 2

ionic bond

Answer 2

An ionic bond is the electrostatic attraction between two ions of opposite charges.

Question 3

metallic bond

Answer 3

A metallic bond is the electrostatic attraction between positively charged metal ions and delocalised electrons.

Question 4

an ion

Answer 4

An ion is a charged particle (an atom or group of atoms that has lost or gained one or more electrons, resulting in a charge and a stable electronic structure).

Question 5

electrostatic attraction

Answer 5

Electrostatic attraction is the attraction between positively-charged and negatively-charged particles (protons & electrons or + and – ions)

Question 6

an ionic lattice

Answer 6

An ionic lattice is the arrangement of ions into a large structure, consisting of alternating positive ions and negative ions.

Question 7

delocalised electrons

Answer 7

Delocalised electrons are not tied to a particular atom, but are free to move throughout a structure. In a metal, these came from the outer shell of the metal atoms.

Question 8

metallic lattice

Answer 8

A metallic lattice is a giant, regular, repeating structure of positive metal ions existing in a ‘sea’ of delocalised electrons.

Question 9

crystal structure

Answer 9

The crystal structure of a substance is the type of structure it has: giant covalent lattice, simple covalent molecular, giant ionic lattice, or giant metallic lattice.

Question 10

dative covalent bond

Answer 10

A dative covalent bond (or co-ordinate bond) is a covalent bond where the shared electron pair comes from only one participating atom.

Question 11

a lone pair

Answer 11

A lone pair is a pair of electrons on an atom’s outer shell that is not being used in a bond. (Can therefore be used to form a dative bond.)

Question 12

electronegativity

Answer 12

Electronegativity is the tendency of an element to attract a shared pair of electrons to itself within a covalent bond.

Question 13

polar bond

Answer 13

A polar bond is formed between atoms with differing electronegativities.

Question 14

permanent dipole

Answer 14

A permanent dipole occurs in a molecule which is asymmetric and has one side which is more positive and one which is more negative.

Question 15

Permanent dipole-permanent dipole interactions

Answer 15

Permanent dipole-permanent dipole interactions occur between molecules which have a permanent dipole.

Question 16

London forces

Answer 16

London forces are instantaneous dipole-induced dipole forces arising from the random movement of electrons in molecules. Their magnitude is mainly influenced by the number of electrons present in a molecule: more electrons leads to stronger London forces. (may also be influenced by how close the molecules can get: closer = stronger). This is the weakest intermolecular force.

Question 17

Hydrogen bonds

Answer 17

Hydrogen bonds exist between molecules that contain a hydrogen atom directly bonded to a N, O or F atom. This is a very strong form of permanent dipole interactions and is the strongest intermolecular force.

Question 18

isoelectronic

Answer 18

Isoelectronic species have the same electronic configuration. (eg. Na+ , F- , and Ar)