1. Physical & Chemical Properties

Question 1

Physical and Chemical properties

Answer 1

• Physical properties are also called macroscopic properties can be easily observed or measured (can include colour),
• Chemical properties are known as microscopic properties because they often cannot be seen, but can be studied through experiments. Properties are described by the substance’s behaviour when reacting with other materials such as acids, bases and water, whether it burns, melts, fizzes, corrodes, or explodes.

Question 2

Melting Point

Answer 2

• The temperature at which a solid changes state to a liquid
• High / low melting point

Question 3

Boiling point

Answer 3

• The temperature at which a liquid boils (vapourises)
• High/low boiling point

Question 4

Volatility

Answer 4

• The ease with which a liquid evaporates
• Volatile/Not volatile

Question 5

Viscosity

Answer 5

• A measure of a substance’s resistance to flow
• Viscous / Runny

Question 6

Transparency

Answer 6

• The ability of a substance to allow light to pass through it
• Transparent / Opaque

Question 7

Opacity

Answer 7

• The ability of a substance to block light from passing through it (impenetrability to light)
• Opaque/Transparent

Question 8

Flexibility

Answer 8

• The ease with which an object can be bent without breaking
• Flexible / Inflexible

Question 9

Brittleness

Answer 9

• The readiness of an object to snap when bent
• Brittle / Malleable or flexible

Question 10

Hardness

Answer 10

• The ability of a substance to resist denting or scratching
• Hard / Soft

Question 11

Elasticity

Answer 11

• The ability of an object to return to its original shape after being stretched
• Elastic / Inelastic

Question 12

Malleability

Answer 12

• The ability of a substance to be extended or shaped by hammering or pressuring with rollers
• Malleable / Brittle or inflexible

Question 13

Ductility

Answer 13

• The ability of a substance to be drawn into a wire
• Ductile / Not ductile

Question 14

Conductivity of Heat

Answer 14

• The degree to which a substance allows heat to flow through it
• Conductor / Non-conductor of heat “insulator”, poor conductor

Question 15

Conductivity of Electricty

Answer 15

• The degree to which a substance allows an electric current to flow through it
• Conductor / Non-conductor or poor conductor of electricity

Question 16

Solubility in Water

Answer 16

• The degree to which a substance dissolves in water
• Soluble / Insoluble in water

Question 17

Density

Answer 17

• The ratio of mass of a substance (grams, g) to its volume (millilitres, mL) D=m/v
• Dense / Not dense
  High density / Low density

Question 18

Durability

Answer 18

• The resistance of a substance to erosion
• Durable (hard-wearing) / Not durable

Question 19

Corrosion

Answer 19

The resistance of a substance to corrosion or rusting is a CHEMICAL property

Question 20

Reactivity

Answer 20

The readiness with which a substance reacts with other substances. A CHEMICAL property

Question 21

Fluidity

Answer 21

• The ability of a substance to flow, characteristic that allows a molecule to move around in space. Liquid and gas are fluids.
• Fluid/solid

Question 22

Biodegradability

Answer 22

• A biodegradable substance can be chemically decomposed (broken down to simpler components) by natural biological processes (e.g. soil bacteria, weather, plants, animals)
• Biodegradable/non-biodegradable

Question 23

Miscibilty

Answer 23

• The physical property of two substances to fully dissolve in each other at any concentration, forming a homogeneous mixture (a solution). The term is most often applied to liquids but can apply to solids and gases.
• Miscible/immiscible

Question 24

5 Signs of a Chemical Change

Answer 24

• Color Change.
• Production of an odor.
• Change of Temperature.
• Dffervescence (formation of bubbles)
• Precipitate (formation of a solid)