Unit 1

Question 1

Dmitri Mendeleev

Answer 1

• 1869
• order of increasing relative atomic mass
• left gaps for undiscovered elements

Question 2

Modern periodic table

Answer 2

• order of atomic number
• rows are called periods
• groups show number of electrons in outer shell

Question 3

mass number

Answer 3

protons + neutrons

Question 4

atomic number

Answer 4

protons

Question 5

isotope

Answer 5

same number of protons but different number of neutrons

Question 6

ionic bonding

Answer 6

metal + non metal

Question 7

properties of ionic compounds

Answer 7

• high melting/boiling points as energy is needed to break bonds
• conducts electricity as solution so ions are free to move
• brittle as layers will shift and like charges repel

Question 8

ball and stick

Answer 8

+ see atom arrangement

- can’t see electrons

Question 9

ionic models

Answer 9

+ clear lattice structure

- doesn’t show electrons

Question 10

displayed formula

Answer 10

+ see the bonds

- doesn’t show electrons

Question 11

dot and cross

Answer 11

+ clearly see electrons

- implies electrons are different

Question 12

covalent bonding

Answer 12

pair of electrons are shared between non metals

Question 13

simple covalent compounds

Answer 13

• low melting/boiling points as weak intermolecular forces
• strong covalent bond as electrostatic forces between nuclei and electrons
• liquid/gas at room temperature

Question 14

giant covalent compounds

Answer 14

• high melting/boiling points
• strong covalent bonds
• dont conduct electricity

Question 15

diamond

Answer 15

• carbon atoms covalently bonded to 4 other atoms
• tetrahedral lattice
• used in cutting tools like drills

Question 16

graphite

Answer 16

• carbon atoms joined to 3 other carbon atoms
• hexagonal layered sheets
• easily slide over each other, used for lubricating
• one delocalised electron to conduct

Question 17

graphene

Answer 17

• sheet of carbon atoms
• high melting point, conducts electricity
• large regular arrangement so its strong

Question 18

properties of metals

Answer 18

• shiny
• high melting points
• conducts
• dense
• malleable

Question 19

properties of non metals

Answer 19

• dull
• low melting points
• doesn’t conduct
• low density
• brittle

Question 20

metallic structure

Answer 20

• delocalised electrons on outer shell
• strong forces of attraction between positive metal ions and electrons
• layers of ions slide over each other

Question 21

moles

Answer 21

mass/RAM

Question 22

JJ Thomson

Answer 22

atoms weren’t solid and discovered electrons inside, so made the plum pudding model

Question 23

Ernest Rutherford

Answer 23

proved plum pudding model wrong with the good foil experiment and discovered the other ions

Question 24

fullerene

Answer 24

large surface area so are good for industrial catalysts