Science Term 2

Question 1

independent variable

Answer 1

a variable that isn’t changed by other variables

Question 2

dependant variable

Answer 2

a variable that changes because of the independent variable and is measured

Question 3

controlled variable

Answer 3

a variable that doesn’t change

Question 4

distillation (how it works)

Answer 4

first, the liquid that has the lower boiling point in the solution is evaporated and the gas is trapped and forced into the condenser which is cooled to form the distillate which goes into the recieving flask

Question 5

filtration (how it works)

Answer 5

you put a funnel into a beaker, then get the filter paper and fold it in half twice. Now put the filter paper into the funnel, which can go in a cronical flask and pour your solution in

Question 6

what are all the stages of heating?

Answer 6

melting and boiling

Question 7

what are the stages of cooling

Answer 7

condensation and freezing

Question 8

how is chromatography used?

Answer 8

used to separate solutions with very small concentrations of coloured solutes.

Question 9

what is paper chromatography
(how to do it)

Answer 9

A solute is dotted on the end of a piece of special chromatography paper. The very end of the paper is then dipped into a solution, and the solute then moves up the paper.

Question 10

can chromatography work on colloids and suspensions?

Answer 10

No

Question 11

what is a solvent

Answer 11

a substance that should easily dissolve the solute

Question 12

what is a solute

Answer 12

a solute is a substance that is meant to be dissolved in the solvent

Question 13

what does dilute mean?

Answer 13

to make a liquid weaker by adding a solvent, such as water

Question 14

what does concentrated mean?

Answer 14

When there is more solute then the solvent

Question 15

what is a heterogeneous mixture?

Answer 15

a heterogeneous mixture is where the solid particles are spread throughout the solution without dissolving in it

Question 16

what is a colloid?

Answer 16

any substance consisting of particles substantially larger than atoms or ordinary molecules but too small to be visible to the unaided eye;

Question 17

what is a homogeneous mixture?

Answer 17

a mixture in which the composition is not uniform throughout the mixture.

Question 18

what does soluble mean?

Answer 18

A substance is dissolvable

Question 19

what does insoluble mean?

Answer 19

A substance cannot be dissolved

Question 20

in chromatography what does the dye that reaches the highest on the paper mean?

Answer 20

It is the most soluble

Question 21

what is sedimentation?

Answer 21

When the solute that hasn’t been dissolved settles at the bottom of the mixture, but not because of gravity

Question 22

What is the distillate

Answer 22

a substance collected after distillation

Question 23

what is resedue

Answer 23

a mixture that is left behind

Question 24

What is expansion?

Answer 24

when heat is added to particles which causes the space between the particles to increase

Question 25

what is density and how do you find it?

Answer 25

the measurement of how many particles are in any given space. you can measure this by D= mass over volume

Question 26

What is Centre fusion

Answer 26

when a substance is spun around and separated according to density. Least dense on top and most dense on the bottom

Question 27

What is a suspension?

Answer 27

when particles that have not been dissolved in a mixture sink to the bottom of the container due to gravity

Question 28

why do objects expand and contract when heated or cooled?

Answer 28

there is an increase/decrease in kinetic energy that causes the particles to vibrate/still and the bonds between them become weaker/stronger