Key concepts

Question 1

What is covalent bonding

Answer 1

When atoms share pairs of electrons

Question 2

What is covalent bonding between

Answer 2

Two non-metallic elements

Question 3

what is a simple molecular compound

Answer 3

are substances composed of molecules held together by covalent bonds

Question 4

properties of a simple molecular compound (boiling point melting point)

Answer 4

low boiling and melting points

Question 5

Structure of a simple molecular compounds in 4 points

Answer 5

-Non-metal elements
-Held together by covalent bonds
-With weak intermolecular forces
- Low boiling/ melting points
-Many insoluble in water

Question 6

Can simple molecular structures conduct electricity, why?

Answer 6

no, small molecules aren’t big enough to be able to carry a charge

Question 7

How are ionic bonds formed

Answer 7

Metal + Non-metal
metals lose an electron: become positive
non-metals gain an electron: become negative

Question 8

What is an ion

Answer 8

an atom which a charge (either positive or negative)

Question 9

What does the suffix ‘-ide’ mean

Answer 9

a compound containing 2 elements

Question 10

What does the suffix ‘-ate’ mean

Answer 10

a compound containing 3 elements

Question 11

What’s the formulae of Oxide

Answer 11

O (-2 ion)

Question 12

What’s the formulae of Hydroxide

Answer 12

OH (-1 ion)

Question 13

What’s the formulae of Halide

Answer 13

-1 halide

Question 14

What’s the formulae of Nitrate

Answer 14

NO3 (-1 ion)

Question 15

What’s the formulae of Carbonate

Answer 15

CO3 (-2 ion)

Question 16

What’s the formulae of Sulphate

Answer 16

SO4 (-2 ion)

Question 17

Describe the structure of an Ionic Lattice in 4 points

Answer 17

1. a giant structure of ions
2. held together by large electrostatic forces
3. Between oppositely charged ions
4. In a regular arrangement

Question 18

Describe the properties of ions (melting and boiling point)

Answer 18

High melting points, High boiling points

Question 19

Can ions conduct electricity, why?

Answer 19

Yes when molten or liquid as they have delocalised electrons that can carry a charge
No when solid

Question 20

What do ions form when dissolved

Answer 20

An aqueous solution

Question 21

How did Mendeleev organise the periodic table

Answer 21

• Order of atomic mass (sometimes weight)
• Left gaps for unknown elements

Question 22

How did Mendeleev predict the existence of unknown elements

Answer 22

Realised groups with similar properties should be in the same group

Question 23

What is a period

Answer 23

a row of chemical elements.
(horizontal)

Question 24

What is a group

Answer 24

a column of chemical elements
(vertical)

Question 25

What is the commonality within groups on the periodic table

Answer 25

Tells you how many electrons upon the outermost shell

Question 26

What is the commonality within periods in the periodic table

Answer 26

show the number of shells of electrons

Question 27

How is the periodic table arranged

Answer 27

* vertical columns based on their properties and the properties of their compounds * horizontally in order of increasing atomic mass

Question 28

How many electrons can an electron hold on it's first fixed shell

Answer 28

2

Question 29

What is the outmost electron shell called

Answer 29

Valence shell

Question 30

Why did the Dalton model of the atom change over time?

Answer 30

Sub-atomic particles were discovered

Question 31

What was the Dalton model

Answer 31

* all matter is made of atoms, which are indivisible. * all atoms of a given element are identical in mass and properties.

Question 32

What did J.J Thompson discover and how

Answer 32

Electrons * used a cathode-ray tube proving atoms as divisible

Question 33

What model did Thompson devise

Answer 33

The plum pudding model * a negatively charged electrons * positive-charged soup

Question 34

What did Ernest Rutherford discover and how

Answer 34

The nucleus * gold foil experiment

Question 35

What was the gold foil experiment

Answer 35

1. Shot a beam of positively charged particles into a sheet of gold 2. Most of the particles did continue in a straight line while some deflected/bounced back

Question 36

What model did Ernest Rutherford discover

Answer 36

The nuclear model * consists of empty space with a nucleus in the middle * electrons orbit the nucleus

Question 37

What is the Bohr Model

Answer 37

* electrons orbit the nucleus in fixed shells

Question 38

Proton Relative charge: Relative mass:

Answer 38

Relative charge: +1 Relative mass: 1

Question 39

Neutron Relative charge: Relative mass:

Answer 39

Relative charge: 0 Relative mass: 1

Question 40

Electron Relative charge: Relative mass:

Answer 40

Relative charge: -1 Relative mass: 1/1836

Question 41

Why do atoms contain equal number of protons and electrons

Answer 41

Atoms are neutral Protons = +1 Electrons = -1 same amount cancel out

Question 42

What is the mass number of an atom

Answer 42

no* of protons + no* of neutrons

Question 43

What is the atomic number of an atom (proton number)

Answer 43

amount of protons (and electrons)

Question 44

How to work out the number of neutrons

Answer 44

mass no*- atomic no*

Question 45

What is an isotope

Answer 45

elements with the same number of protons but different number of neutrons

Question 46

Why are some relative atomic masses not whole numbers

Answer 46

isotopes have different masses, the relative atomic mass of an element is calculated by the weighted average of the masses.

Question 47

How do you calculate R.A.M (relative atomic mass)

Answer 47

(mass of isotope-A x % of isotope-A) + (mass of isotope-B x % of isotope-B) ÷100