TEST

Question 1

when a solid is heated

Answer 1

When a solid is heated, particles vibrate faster about a fixed point causing particles to move further apart and so solid expands

Question 2

when particles get sufficient energy

Answer 2

When particles gain sufficient energy to overcome strong forces of attraction, they move out of their fixed position and can slide over each other in a continuous random motion – solid has melted.

Question 3

particles in liquid

Answer 3

Particles in liquid have energy to move around but are still close to each other and do not have enough energy to overcome the forces that hold them close to each other.

Question 4

if more heats supplied

Answer 4

If more heat’s supplied, particles move faster until they have enough energy to overcome the forces of attraction. Particles escape the liquids surface and move around in continuous rapid motion – the liquid has boiled

Question 5

in the vapour

Answer 5

In the vapor, the particles move in rapid random motion. This movement is due to collision of vapor particles with air particles.

Question 6

solid

Answer 6

Strong forces of
attraction between
particles
 Fixed pattern
(lattice)
 Atoms vibrate but
can’t change
position ∴ fixed
volume and shape

Question 7

liquid

Answer 7

Weaker attractive
forces than solids
 No fixed pattern,
liquids take up the
shape of their
container
 Particles slide past
each other.

Question 8

gas

Answer 8

Almost no
intermolecular
forces
 Particles far apart,
and move quickly
 Collide with each
other and bounce
in all directions

Question 9

endothermic heat energy gained

Answer 9

melting
boiling
sublimation

Question 10

diffusion

Answer 10

Diffusion is the spreading of one substance through another from a
region of high concentration to a region of low concentration due to
the continuous random motion of particles.

Question 11

it is endothermic because

Answer 11

energy is needed to overcome the force of attraction between molecules

Question 12

gas at room temp

Answer 12

chlorine

Question 13

non mettalic liquid at room temp

Answer 13

bromine

Question 14

compound which is solid at room temp

Answer 14

sodium chloride

Question 15

why is it towards hcl

Answer 15

because ammonia difusses faster and it has a lower mass

Question 16

Type of chemical reacyion between ammonia and hcl

Answer 16

neutralization

Question 17

copper oxide color

Answer 17

black

Question 18

red brown solid

Answer 18

copper

Question 19

drops of liquid

Answer 19

water

Question 20

physical test to find thee liquid

Answer 20

its water so just check the boiling and freezing point 0 and 100 degree celcius

Question 21

arrangement of motion of atoms from condensation to solidification
gas liq sol

Answer 21

atoms of gas are randomly arranged and the atoms move very fast.slow down during condensation move slower.Atoms are close together and can slide over each other.During freezzing atoms further slow down and become more regularly arranged and can only vibrate

Question 22

when is it a liquid

Answer 22

when its mp is below room temp and bp is above room temp m.p is -79 degree celc and bp is 138 room temp is between boiling and melting point

Question 23

Factors that affect the rate of diffusion:

Answer 23

Temperature increases → rate of diffusion increases

o Lower density gas → rate of diffusion is higher

Question 24

Assesing purity from m.p./b.p:

Answer 24

Pure substances have a definite, sharp m.p./b.p.
o Substance+impurity has lower m.p. and higher b.p.
o More impurity means bigger change

Question 25

filtration

Answer 25

``` Mixture goes in a funnel with filter paper, into a flask.  Residue is insoluble and stays at top.  Filtrate goes through. ```

Question 26

Crystalization

Answer 26

``` Some water in the solution is evaporated so solution becomes more concentrated.  A drop is placed on a slide to check if crystals are forming.  Solution is left to cool and crystallise.  Crystals are filtered to remove solvent. ```

Question 27

Simple distillation

Answer 27

``` Impure liquid is heated  It boils, and steam rises into the condenser  Impurities are left behind  Condenser is cold so steam condenses to the pure liquid and it drops into the beaker ```

Question 28

fractional distillation

Answer 28

``` Removes a liquid from a mixture of liquids, because liquids have different b.p.s  Mixture is heated to evaporate substance with lowest b.p.  some of the other liquid(s) will evaporate too.  A mixture of gases condense on the beads in the fractional column.  So the beads are heated to the boiling point of the lowest substance, so that substance being removed cannot condense on the beads.  The other substances continue to condense and will drip back into the flask.  The beaker can be changed after every fraction. ```

Question 29

The proton number increases

Answer 29

by 1 when you go to the right

Question 30

When you go one element down

Answer 30

you increase proton number | by 8 in the first 3 periods

Question 31

isotope

Answer 31

Isotopes: atoms of same element with different no. of neutrons o E.g. Carbon 12 and Carbon 14.

Question 32

isotope medical

Answer 32

Medical use: cancer treatment (radiotherapy) – rays kill cancer cells using cobalt-60

Question 33

industrial use

Answer 33

to check for leaks – radioisotopes (tracers) added to oil/gas. At leaks radiation is detected using a Geiger counter.

Question 34

element

Answer 34

that cannot be split into anything simpler, in a | chemical reaction. Each element has a unique proton number.

Question 35

mixture

Answer 35

two or more elements mixed together but not | chemically combined

Question 36

compouns

Answer 36

substance in which two or more different elements | are chemically combined

Question 37

metals non metals

Answer 37

``` Metals Non-metals Strong Brittle Good conductors of heat & electricity Poor conductors of heat & electricity (except graphite) High m.p. and b.p. Lower m.p. and b.p. than metals High density Low density Forms basic oxides Forms acidic oxides Forms cations in reactions Forms anions in reactions Malleable and ductile Sonorous Some are magnetic ```

Question 38

alloy

Answer 38

Mixture of two or more metals or mixture of one or more | metal with a non-metal, to improve its properties

Question 39

ionic bonding

Answer 39

Strong electrostatic force of attraction between positive cations and negative anions is called ionic bonding

Question 40

ionic property reason

Answer 40

``` Property Reason Form giant lattice Cations and anions attract High m.p. and b.p. Strong bonds between ions Don’t conduct electricity when solid Ions can’t move Conduct electricity when molten/aqueous Ions can move Usually soluble in water Not required ```

Question 41

covalent bonds

Answer 41

When atoms share 𝑒̅s to obtain a noble gas electron structure  Covalent bonding takes place between non-metals only

Question 42

covalent compound property and reason

Answer 42

Property Reason Low m.p. and b.p. Weak intermolecular forces of attraction Usually liquid, gas or low m.p solid between molecules Don’t conduct electricity No mobile ions/electrons Usually insoluble in water Not required

Question 43

diamond

Answer 43

``` Four bonds  High m.p.  Doesn’t conduct  Used for cutting as is srongest known substance ```

Question 44

graphite

Answer 44

``` Three bonds  Made of flat sheets  Held together by weak forces so is soft and slipperyused as a lubricant  Conducts electricity because it has one free electron. ```

Question 45

silicon dioxide

Answer 45

```  Makes up sand  Each Si is bonded to 4 oxygen atoms, and each oxygen is bonded to 2 silicon atoms  it has a high m.p. and is hard, like diamond ```

Question 46

Melting point: high

Answer 46

structure made up of strong covalent bonds

Question 47

strength

Answer 47

Strength: hard - exists in tetrahedral structure but graphite is soft

Question 48

mettalic bonding

Answer 48

metals are good conductors of electricity as free electrons can carry charge why good conductor of heat and electricity strong electrostatic force of attraction between positive metal ions and free electrons is mettalic bond Layers are held together by delocalized electrons.