Acids, Bases And PH

Question 1

What is the law of conservation of matter?

Answer 1

Matter can never be destroyed or created but it can be changed

Question 2

What happens to the matter when you burn up wood since it cant be destroyed?

Answer 2

• the solid materials are transformed into chemical gases and solid ash
• all the atoms still making up the wood still exist but in a different form

Question 3

What are the two types of changes that can happen to matter?

Answer 3

Physical change and chemical changes

Question 4

What is the definition of a physical change?

Answer 4

A change where the matter looks different but is still made of the same substance of chemical

Question 5

When do physical changes happen?

Answer 5

• you need to add energy or a force

- when you change the temperature or pressure

Question 6

What is the definition of a chemical change?

Answer 6

A change where a new substance or chemical is formed.

Question 7

How can you tell if its a chemical change?

Answer 7

1. A new solid has formed
2. A new gas has formed (bubbles, an explosion, a smell, a visible gas)
3. A new color is visible that doesnt go away
4. A change in temperature
5. A pH change

Question 8

What are reactants?

Answer 8

The chemicals you mix in a chemical reaction

Question 9

What are products?

Answer 9

The chemicals you make

Question 10

Physical or chemical change? Chocolate melts

Answer 10

Physical

Question 11

Physical or chemical change? Iron rusts

Answer 11

Chemical

Question 12

Physical or chemical change? Breathing

Answer 12

Chemical

Question 13

Physical or chemical chnage? Salt dissolves in water

Answer 13

Physical

Question 14

What does pH mean?

Answer 14

Ph stands for potential of Hydrogen. The pH scale goes from 0-14.

Question 15

What’s the definition of acid?

Answer 15

A substance that has a pH between 0 and 6.9.

Question 16

What’s the definition of a base?

Answer 16

A substance that has a pH between 7.1 and 14

Question 17

What’s the definition of neutral?

Answer 17

Something thats neither acidic or basic. Has a pH of 7.0

Question 18

Litmus paper

Answer 18

Tells you weather its an acid or a base.

Basic=both papers turn blue
Acid=both papers turn red
Neutral=both papers stay the same colour

Question 19

What Is photosynthesis?

Answer 19

It is whne you make sugar (glucose) and oxygen out of carbon dioxide water and light.

Question 20

Where does photosynthesis happen?

Answer 20

In the chloroplasts > in the cells > in the green parts > in all plants

Question 21

What materials go in the plants during photosynthesis?

Answer 21

Carbon dioxide (co2) + light energy + water (h2o)

Question 22

What materials come out of plants during photosynthesis?

Answer 22

Sugar (c6h12o6) + oxygen

Question 23

Why are plants called producers?

Answer 23

Because they can produce and create their own food