3.1 - Introduction

Question 1

What make good observations?

Answer 1

• Solid, liquid or gas?
• Coloured or colourless?
• Crystalline or powdered? (for solids)
• Clear or cloudy? (for liquids)

Question 2

Things that make a physical change physical.

Answer 2

• Create no new substances.
• Are usually easy to reverse
• Absorb or release small amounts of energy.

Question 3

What things that make a chemical change chemical.

Answer 3

• Create new substances.
• Are usually difficult to reverse.
• Absorb or release large amounts of energy

Question 4

Tests For Water

One chemical test for water is?

Answer 4

Anhydrous copper(II) sulphate: turns from white to blue

Question 5

One example of a physical tests for water is?

Answer 5

Melting point (MP) = 0 oC

Question 6

Another example of a physical tests for water is?

Answer 6

Boiling point (BP) = 100 oC

Question 7

What is a solute?

Answer 7

The substance which is going to be dissolved

Question 8

What is a solvent?

Answer 8

The liquid which is going to do the dissolving

Question 9

What is a solution?

Answer 9

The resulting mixture of solute dissolved in solvent

Question 10

What is a saturated solution?

Answer 10

A solution in which no more solute can be dissolved

Question 11

What is a suspension?

Answer 11

A solid floating in a liquid because it cannot dissolve

Question 12

What does soluble mean?

Answer 12

A substance which can be dissolved

Question 13

What does insoluble mean?

Answer 13

A substance which can’t be dissolved

Question 14

We measure solubility per how many grams?

Answer 14

We measure solubility in g per 100 g of solvent

Question 15

Solubility varies with what?

Answer 15

Solubility varies with temperature.

Question 16

On a solubility graph the line shows what?

Answer 16

Shows the maximum mass of solid which can be dissolved at each temperature.

Question 17

On a solubility graph the part above the line shows what?

Answer 17

More than the maximum mass of solid, so some will dissolve and some won’t.

Question 18

On a solubility graph the bit below the line shows what?

Answer 18

Less than the maximum mass of solid, so it will all dissolve.

Question 19

what is the definition of an element?

Answer 19

An element is a substance containing only one type of atom.

Question 20

What are the properties of non-metals?

Answer 20

Non - Metal Properties:
Low MP/BP 
Electrical insulators
Brittle
Dull

Question 21

What are the properties of metals?

Answer 21

Metal Properties:
High MP/BP 
Electrical conductors
Malleable
Shiny

Question 22

Where can you find the symbols for elements?

Answer 22

For most elements, their chemical formula is also their symbol from the periodic table.

Question 23

Which elements are diatomic?

Answer 23

Hydrogen - H2
Nitrogen - N2
Oxygen - O2
Fluorine - F2
Chlorine - Cl2
Bromine - Br2
Iodine - I2
Astatine - At2

Question 24

What shape do diatomic elements take.

Answer 24

Number 7 plus hydrogen.

Question 25

What is the definition of a compound?

Answer 25

A compound is a substance containing more than one type of atom, chemical bonded together.

Question 26

How can compounds be formed?

Answer 26

Compounds can often be formed by heating their elements together.

Question 27

True or false:

The properties of a compound are identical to the properties of the elements it was made from.

Answer 27

False:
The properties of a compound are usually totally different from the properties of the elements
the compound is made from.

Question 28

Finish the sentence:

There are three types of compound, each containing a different type of chemical ___________.

Answer 28

Bonding