Matters, materials and processes term 2

Question 1

Name the characteristics of a solid

Answer 1

atoms are tightly packed, they are fixed and cannot move past each other. They have a defined shape and volume. When heat is added a solid may melt becoming a liquid. When a solid becomes a gas it is called sublimation.

Question 2

When a solid is changed it gas without passing through the liquid it is called…

Answer 2

sublimation

Question 3

Name the characteristics of a liquid

Answer 3

The atoms are close but loosely packed together. They can move past each other. They have a defined volume but not shape - they will take the shape of the container they are in. When heat is added it becomes a gas and the process is called evaporation. When liquid changed to solid it is called solidification.

Question 4

When gas changes to a liquid it called…

Answer 4

condensation

Question 5

When liquid changes to gas it is called…

Answer 5

evaporation

Question 6

Name the characteristics of a gas

Answer 6

atoms far apart, lots of space in between, they can move past each other. No defined shape or volume. When gasses are not contained they are able to spread everywhere.

Question 7

A gas becomes a solid in a process called

Answer 7

disposition

Question 8

Density is

Answer 8

how much mass a substance has in a given space

Question 9

Boiling point is…

Answer 9

the temperature in which a liquid becomes a gas

Question 10

Melting point is…

Answer 10

The temperature in which a solid becomes a liquid

Question 11

Freezing point is…

Answer 11

The temperature in which a liquid becomes a solid

Question 12

Solubility is…

Answer 12

The ability of one substance to dissolve in another is called its solubility. Said another way solubility is the amount of solute that can be dissolved into a solvent. e.g. corenzo has a high solubility because it completely dissolves. Insoluble substances won’t dissolve so they will either float or sink in the liquid.

Question 13

What is a solvent?

Answer 13

The liquid in which the substance dissolves is called the solvent

Question 14

What is a solute?

Answer 14

the substance that dissolves in the liquid in the solute

Question 15

What is a mixture?

Answer 15

2 or more substances mixed together without a chemical reaction taking place

Question 16

How is a compound formed?

Answer 16

When 2 different substances are mixed together and end up creating a chemical reaction

Question 17

What are the differences between compounds and mixtures?

Answer 17

Compounds have a chemical reaction and mixtures dont. In many cases mixtures can be seperated - where compounds cant be.

Question 18

What are peanuts and raisins? Compound or mixture?

Answer 18

solid and solid - mixture

Question 19

What is mud? Compound or mixture?

Answer 19

mixture - liquid and solid

Question 20

what is oil and vinegar?

Answer 20

mixture - liquid and liquid

Question 21

Some mixtures can be separated - how? Give an example of when you would choose each method

Answer 21

Sieving (when one substance is bigger than other in mixture e.g. beans and sand), hand sorting (when the different substances of a mixture are big enough to be handled eg. peanuts and raisons), filtering (use when separating insoluble solids from a liquid) and settling and decanting (when one liquid is combined with a denser other liquid or insoluble solid)

Question 22

What are solutions?

Answer 22

combination of 2 or more substances in an even distribution. Uniform in appearances. Solute can not be seen once it has dissolved. It is made up of a solvent and a solute - solute is smallest quantity and solvent bigger quantity.

Question 23

What is dissolving?

Answer 23

When a substance seems to disappear in a liquid e.g. sugar dissolving in water
The solid is still present in the solution, but has been broken down into smaller pieces which are invisible to the human eye. The particles of the solute will become dispersed in the spaces between the solvent particles. Dissolving can be reversed.

Question 24

What factors affect solubility?

Answer 24

Temperature of the solution - heat - dissolves quicker
Grain size of the solute - the larger the grain of solute the slower it will dissolve
Movement - stirring or shaking - increases rate - brings the solvent into contact with the solute quicker and also breaks the solute into smaller pieces.