Chapter 3: Exploring Diversity of Matter by its Chemical Composition

Question 1

What is a compound?

Answer 1

A compound consists of two or more elements that are chemically combined together.

Question 2

Do compounds have the same properties as their constituent elements?

Answer 2

No.
E.g. Hydrogen(gas) + Oxygen(gas) = Water(liquid)
The gases are the constituent elements and the water is the compound.

Question 3

What is a mixture?

Answer 3

A mixture is made up of two or more elements and/or compounds that are NOT chemically combined. (Two or more elements only/ two or more compounds only/ one or more elements and compounds)

Question 4

Composition of an element is..

Answer 4

Only one element (so it’s pure)

Question 5

How are elements formed?

Answer 5

Mostly a naturally occurring process

Question 6

How is a compound formed?

Answer 6

A chemical reaction

Question 7

How is a mixture formed?

Answer 7

A physical change

Question 8

Proportion of constituents in mixtures are…

Answer 8

Not fixed.

Question 9

Recap: proportions of constituents in compounds are..

Answer 9

Fixed.

Question 10

Properties of compounds from their constituents are..

Answer 10

Not the same, not kept.

Question 11

Properties of a mixture of it constituents are…

Answer 11

The same, kept.

Question 12

Recap: separation of constituents in compounds is…

Answer 12

Not easy

Question 13

Separation of constituents in mixtures is…

Answer 13

Easy

Question 14

What is a solution?

Answer 14

A mixture in which one substance dissolves completely in another substance

Question 15

The substance that dissolves is called the…

Answer 15

Solute (it dissolves)

Question 16

The substance in which the solute dissolves is called the..

Answer 16

Solvent (it makes the dissolving dissolves)

Question 17

Factors of the rate of dissolving

Answer 17

1. Size of solute particles
2. Temperature of solvent
3. Rate of stirring

Question 18

Would the volume of a solvent affect the rate of dissolving if all other factors or variables are kept the same?

Answer 18

Yes, but not the rate.

E.g. making hot milo and u pour more hot water to make the milo powder dissolve faster.

Question 19

What is solubility?

Answer 19

Solute is the maximum amount of solute that can dissolve in a fixed amount of solvent at a fixed temperature

Question 20

What is a suspension?

Answer 20

A mixture that contains insoluble substances in a solvent

Question 21

Can particles of the solute be seen in a solution?

Answer 21

No.

Question 22

Can insoluble substances be seen in a suspension?

Answer 22

Yes

Question 23

Can light pass through solution and suspension?

Answer 23

For solutions, light can pass through fully while for suspensions, light cannot pass through fully.

Question 24

Does the solute in a solution settle to form solid deposits?

Answer 24

No. While for suspension, insoluble substances can settle to form solid deposits.

Question 25

How do you know if an element has the same chemical properties as another?

Answer 25

Elements in the same group have similar chemical properties and will undergo the same type of chemical reactions.