chemical Change

Question 1

Chemical Change

Answer 1

change that results in a new substance being formed. During a chemical change, some chemical bonds break and others form.

Question 2

Evaporation

Answer 2

change state from a liquid to a gas. Evaporation occurs only from the surface of a liquid.

Question 3

state

Answer 3

condition or phase of a substance. The three main states of matter are solid, liquid and gas.

Question 4

physical changes

Answer 4

change in which no new chemical substances are formed. A physical change may be a change in shape, size or state. Many physical changes are easy to reverse.

Question 5

chemical reaction

Answer 5

a chemical change in which one or more new chemical substances are produced

Question 6

reactants

Answer 6

chemical substance used up in a chemical reaction. Some chemical bonds in a reactant are broken during the reaction.

Question 7

products

Answer 7

new chemical substance that results from a chemical reaction

Question 8

precipitate

Answer 8

solid product of a chemical reaction that does not dissolve in water

Question 9

Rusting

Answer 9

the corrosion of iron

Question 10

Corrosion

Answer 10

a chemical reaction that wears away a metal. Air, water or chemicals in air and water, as well as many household substances, can be corrosive. Many acids and other corrosive substances are dangerous.

Question 11

rust

Answer 11

a brown substance formed when iron reacts with oxygen and water

Question 12

surface Protection

Answer 12

coating over a metal surface to prevent corrosion

Question 13

Galvanizing

Answer 13

protecting a metal by covering it with a more reactive metal that will corrode first

Question 14

Burning

Answer 14

combining a substance with oxygen in a flame

Question 15

oxidation

Answer 15

chemical reaction involving the loss of electrons by a substance

Question 16

fossil fuels

Answer 16

substance, such as coal, oil and natural gas, that has formed from the remains of ancient organisms. Coal, oil and natural gas are often used as fuels; that is, they are burnt in order to produce heat.

Question 17

combustion

Answer 17

the process of combining with oxygen, most commonly burning with a flame

Question 18

Nylon

Answer 18

synthetic fibre. The monomers are joined by the elimination of water molecules at the joins.

Question 19

Polyester

Answer 19

synthetic fibre. The monomers are joined together by the elimination of water molecules at the joins.

Question 20

spinneret

Answer 20

device like a nozzle with small holes through which a plastic material passes, forming threads

Question 21

durability

Answer 21

the quality of lasting, not easily being worn out

Question 22

elastic

Answer 22

describes a material that is able to return to its original size after being stretched

Question 23

biodegradable

Answer 23

describes a substance that breaks down or decomposes easily in the environment

Question 24

organisms

Answer 24

living things

Question 25

Cullet

Answer 25

used glass

Question 26

recycled

Answer 26

reused an unwanted substance or object for another purpose

Question 27

sustainable

Answer 27

describes the concept of using the Earth’s resources so that the needs of the world’s present population can be met, without damaging the ability of future populations to meet their needs

Question 28

independent and dependent variables

Answer 28

Dependent and independent variables are variables in mathematical modeling, statistical modeling and experimental sciences