chem

Question 1

what do metals in groups 1,2,3 form

Answer 1

+1, +2, +3

Question 2

what do non-metals in groups 5, 6, 7 form

Answer 2

-3, -2, -1

Question 3

what are the first four orbitals called

Answer 3

S, P, D, F

Question 4

what are s orbitals shaped like

Answer 4

they are shaped like a sphere

Question 5

what are p orbitals shaped like

Answer 5

they are shaped like a dumb-bell

Question 6

how many electrons can s orbitals hold

Answer 6

2 electrons

Question 7

how many electrons can p orbitals hold

Answer 7

up to 6 electrons

Question 8

how many electrons can d orbitals hold

Answer 8

up to 10 electrons

Question 9

how many electrons can f orbitals hold

Answer 9

up to 14 electrons

Question 10

where is the S block found

Answer 10

the first two groups of the periodic table

Question 11

where is the D block found

Answer 11

transition metals (between S and P) in the periodic table

Question 12

where is the P block found

Answer 12

on the right hand side of the periodic table (3-8)

Question 13

where is the F block found

Answer 13

bottom 2 rows of the periodic table

Question 14

what is a lattice

Answer 14

a regular 3 diensional pattern of ions

Question 15

what are positive ions

Answer 15

• generically formed by metal atoms losing elecrons and are found in groups 1,2 and 3
• known as cations.
• have a postive charge

Question 16

what are negative ions

Answer 16

• formed by non metal atoms gaining electrons.
• have a negative charge
• sometimes exists as polyatomic ions (OH-, CO3 2-) (SO4 2-)
• known as anions

Question 17

what are covalent bonds

Answer 17

covalent bonds are formed when atoms share a pair of electrons

Question 18

what are metallic bonds

Answer 18

a strong electrostatic attraction between the positive metal and delocalised electron

Question 19

what are properties of metals

Answer 19

• high melting and boiling point due to strong electrostatic attractions between positive and negative ions and electrons.
• conducts electricity and heat due to delocalised electrons making them free to move.
• malleability as layers of positive ions slides over each other and the delocalised electrons.

Question 20

what are intermolecular forces

Answer 20

interactions between molecules caused by either permanent/ induced dipoles.

Question 21

what are polar molecules

Answer 21

• they have permanent dipoles because of the dipole interaction.
• the molecules are attracted to eachother, these weak attracted forces are called permanent dipole-dipole interaction (chemical attraction)

Question 22

what is a london force

Answer 22

• when electrons move around an atom, they cause an uneven distribution in the atom resulting in temporary dipole.
• this will result in a weak attraction.
• the more electrons, the more likely the process will occur so the stronger the London force.

Question 23

Why can only O, F and N atoms form hydrogen bonds

Answer 23

theyre small and highly electronegative (they pull pairs of electrons towards them)

Question 24

what bonds do water bonds form between each other

Answer 24

• they form hydrogen bonds between each other.

- hydrogen bonds have strong intermolecular forces

Question 25

what do you have to remember when drawing hydrogen bonds between molecules

Answer 25

• show the dipole charge on relevant atoms.
• show the pairs of electrons on O, N or F.
• indicate the hydrogen bond clearly eg using a dashed line.

Question 26

what is the relative formula mass

Answer 26

the sum of the relative atomic masses of all the atoms in the formula of the substance

Question 27

what is the formula for mole

Answer 27

mole= mass/ molar mass (relative formula mass)

Question 28

what is the reactivity series (from least reactive to most reactive)

Answer 28

• lithium
• sodium
• potassium
• rubidium
• caesium
• francium

Question 29

why does the reactivity increase in the reactivity series

Answer 29

• the atoms get larger as you go down the group
• the outer shell electron gets further away from the nucleus
• the further the electron is from the positive nucleus, the easier it is to lose in a reaction

Question 30

what does a metal oxide + acid equal

Answer 30

salt + water

Question 31

what does a metal + acid equal

Answer 31

salt + hydrogen

Question 32

what are the rules for assigning oxidation numbers (the charge that the atom has)

Answer 32

1. an element on its own has an oxidation number of zero
2. for a simple ion, the oxidation number is the charge of the ion
3. in a compound, the sum of the oxidation states is zero
4. the sum of the oxidation numbers equals the charge on a complex ion

Question 33

what is the Avogadro’s law

Answer 33

equal volumes of different gases at the same pressure and temperature will contain equal numbers of particles

Question 34

how do you calculate the mass of a product when given the mass of a reactant

Answer 34

1. calculate the number of moles of reactant (Mol= Mass/Mr)
2. determine mole ratio of reactant to product: ensure the equation is balanced
3. calculate the number of moles of the product:
   use the mole ratio
4. calculate the mass of the product:
   (Mass=Moles x Mr)

Question 35

what is the formula for concentration

Answer 35

concentration= moles/ volume

Question 36

how do you go from kg to g

Answer 36

x 1000

Question 37

how do you calculate the percentage yield

Answer 37

actual yield/ theoretical yield X100