Unit 1

Question 1

Properties of a giant ionic structure

Answer 1

High melting point
Brittle
Conductivity

Question 2

What is a covalent bond

Answer 2

Two non metals sharing a pair of electrons

Question 3

What is the attraction between electrons and the nucleus called

Answer 3

Electrostatic attraction

Question 4

What is average bond enthalpy

Answer 4

Degree of strength a covalent bond has

Question 5

What is a dative bond

Answer 5

A covalent bond where both electrons come from the same atom

Question 6

How do you demonstrate a dative bond

Answer 6

Arrow points from the atom donating the lone pair to the atom accepting it

Question 7

What is it called when an atom doesn’t have all the electrons it could

Answer 7

Electron deficient

Question 8

What is the basic theory of shapes of molecules

Answer 8

Molecules take up the shape that minimises repulsion between electron pairs within the molecule

Question 9

What do dotted lines and wedges show

Answer 9

Dotted- bond going away

Wedge- bond coming towards

Question 10

What is Electronegativity

Answer 10

the ability of an atom in a covalent bond to attract the bonded pair electrons

Question 11

As you go down a group, what happens to Electronegativity

Answer 11

Decreases

Due to increased shielding

Question 12

What happens to Electronegativity across a period

Answer 12

Increases due to the increasing nuclear charge decreasing the size of the atoms

Question 13

what is a pure covalent bond

Answer 13

where the electrons are shared evenly between the 2 atoms

Question 14

what is a polar bond

Answer 14

one end is slightly positive and the other slightly negative

Question 15

what is a permanent dipole

Answer 15

the two opposite charges within the molecule are poles

Question 16

how to calculate charge density

Answer 16

charge of the ion/ionic radius

Question 17

how does polarising ability change

Answer 17

increases as the positive ion gets smaller and the number of charges gets larger

Question 18

what are intermolecular attractions

Answer 18

attractions between one molecule and a neighbouring molecule

Question 19

what is a permanent dipole/ permanent dipole attraction

Answer 19

occurs between polar molecules which have a permanent dipole

Question 20

what is hydrogen bonding

Answer 20

dipole-dipole attraction

hydrogen bond must be attached to N, O, F electrons on the electronegative atom

Question 21

what are London forces

Answer 21

temporary dipole- induces a dipole attraction- but is constantly changing as electrons move around

Question 22

what happens to London forces as molecules get bigger

Answer 22

number of electrons increases, making the molecule more polarisable, producing greater induced dipole attractions

Question 23

if a gas, liquid has a low melting point what does this tell you

Answer 23

covalently bound molecules

Question 24

what does it tell you if something is soluble

Answer 24

hydrogen bonding

Question 25

what does a high melting point solid suggest

Answer 25

giant ionic/metallic/covalent