Elements Of Life

Question 1

What is atomic number?

Answer 1

The number of protons in an atom

Question 2

What is mass number?

Answer 2

The total number of protons and neutrons

Question 3

What is relative atomic Mass?

Answer 3

Mean weighted mass of an Atom of an element compared with 1/12 Mass of an atom of carbon-12

Question 4

What is relative molecular Mass?

Answer 4

Mean weighted mass of a molecule compared with 1/12 Mass of an atom of carbon-12

Question 5

What is relative formula Mass?

Answer 5

Sum of all mean weighted masses of all atoms in the formula of a compound compared with 1/12 the Mass of an atom of carbon-12

Question 6

What is relative isotopic Mass?

Answer 6

Mass of an atom isotope compared with 1/12 the Mass of an atom of carbon-12

Question 7

What is the mole?

Answer 7

The amount of substance containing as many particles as there are atoms in 12g of carbon-12. 1 mole = 6.02x10^23 items

Question 8

How is percentage yield calculated?

Answer 8

Percentage yield= (actual yield/ theoretical yield) x100

Question 9

What shape are s and P orbitals?

Answer 9

S= spherical, p= dumb-bell

Question 10

How are electrons arranged in orbitals?

Answer 10

Electrons fill from the lowest energy level first. Electrons will occupy orbitals by themselves end will only pair if no other energy orbitals are available.

Question 11

What is fusion and what conditions are needed?

Answer 11

When two lighter nuclei collide and combine to form a heavier nucleus, releasing energy.
Very high temperature and pressure.

Question 12

What is covalent bonding?

Answer 12

The electrostatic attraction between a par of shared electrons and two positive nuclei

Question 13

Why are ion’s substances only conductive when dissolved?

Answer 13

When they are dissolved the ions are free to move so can carry a charge

Question 14

Why do covalent and ionic lattices have high melting points?

Answer 14

Both lattices contain atoms that have strong and regular bonds around them which require a lot of energy to overcome.

Question 15

2 bonding groups
2 lone pairs

Answer 15

Non-linear
104.5°

Question 16

3 bonding groups
O lone pairs

Answer 16

Trigonal planar
120°

Question 17

2 bonding groups
0 lone pairs

Answer 17

180°
Linear

Question 18

2 bonding groups
1 lone pair

Answer 18

Non-linear
120°

Question 19

4 bonding groups
0 lone pairs

Answer 19

Tetrahedral 109°

Question 20

3 bonding groups
1 lone pair

Answer 20

Pyramidal
107°

Question 21

5 bonding groups
0 lone pairs

Answer 21

Trigonal bipyramidal
120° + 90°

Question 22

6 bonding groups
0 lone pairs

Answer 22

Octahedral
90°

Question 23

How do different numbers of bonded and lone pairs produce different shapes in molecules?

Answer 23

Lone pairs repel more than bonded groups

Question 24

What is ionic bonding?

Answer 24

The electrostatic attraction between ions of opposite charge

Question 25

What is first ionisation enthalpy?

Answer 25

The enthalpy change that occous when one mole of electrons is removed from one mole of gaseous atoms

Question 26

What does the group number represent?

Answer 26

Number of electrons in outer energy level

Question 27

What does the period number represent?

Answer 27

Number of energy levels in the atom

Question 28

Why does first ionisation enthalpy increase across a period?

Answer 28

Same number of electron shells but number of protons in the nucleus increases therefore increasing force of attraction between nucleus and outer electrons

Answer 29

-

Question 30

What is molecular formula?

Answer 30

Actual number of atoms in a molecule

Question 31

What is empirical formula?

Answer 31

Smallest whole number ratio of atoms in a compound

Question 32

How do you calculate water of crystalisation?

Answer 32

Calculate number of moles of water and anhydrous salt (mass/mr= moles) Divide moles of water by moles of anhydrous salt to get x

Question 33

How do you calculate % atom economy?

Answer 33

% atom economy = (Mr of desired product/Mr of all product)x 100

Question 34

What is an acid?

Answer 34

An H+ donor

Question 35

How do you prepare a standard solution of acid (6 marks)

Question 36

Define electronegativity

Answer 36

Ability of an atom to attract electrons in a covalent bond

Question 37

Define metallic bonding.

Answer 37

Electrostatic attraction between metal cations and a sea of delocalised elections

Question 38

How do the charge densities of group 2 ions affect the thermal stability of their carbonates?

Answer 38

Smaller ions with the same charge have higher charge densities so distort the carbonate ions more

Question 39

How can you test for Fe2+ ions?

Answer 39

Add OH- ions, a green ppt will form

Question 40

How can you test for Fe3+ ions?

Answer 40

Add OH- ions, a brown ppt will form

Question 41

What is the thermal decomposition of group 2 carbonates?

Answer 41

All group 2 carbonates undergo thermal decomposition to produce a metal oxide and carbon dioxide The carbonate and metal oxide are both white solids, carbon dioxide is a colourless gas

Question 42

What is the solubility rule for group 2 carbonates?

Answer 42

Solubility decreases down the group, however none are very soluble

Question 43

What is the solubility rule for group 2 hydroxides?

Answer 43

Solubility increases down the group

Question 44

What hopes to first ionisation enthalpy down a group and across a period?

Answer 44

Down the group - First ionisation enthalpy decreases due to increasing atomic radius and electron shielding which reduce the effect of electrostatic forces of attraction Along a period - First ionisation enthalpy increases due to decreasing atomic radius (from increasing nuclear charge) and greater electrostatic forces of attraction

Question 45

What does an emissions spectrum look like?

Answer 45

Bright lines on a dark background

Question 46

What does an absorption spectrum look like?

Answer 46

Dark lines on a coloured background

Question 47

What do both absorption and emission spectra have in common?

Answer 47

Both are line spectra The lines are in the same position for any given element Lines become closer at higher frequencies Both a series of lines representing transitions to or from a particular energy level

Question 48

Lithium ion flame colour

Answer 48

Crimson red

Question 49

Sodium ion flame colour

Answer 49

Yellow

Question 50

Potassium ion flame colour

Answer 50

Lilac

Question 51

Calcium ion flame colour

Answer 51

Brick red

Question 52

Barium ion flame colour

Answer 52

Green

Question 53

Copper(II) ion flame colour

Answer 53

Blue-green