Science - Chapter 7.1 & 7.2

What is air made up of?

78% nitrogen, 21% oxygen, 0.9% noble gases, 0.07% water vapour and other gases, 0.03% carbon dioxide,

What are the 3 main noble gases in air?

argon, helium, neon

How does the burning splint react to oxygen?

it burns more brightly

How does the glowing splint react to oxygen?

it relights

How does the burning splint react to carbon dioxide?

it goes out

How does the glowing splint react to carbon dioxide?

it goes out

How does the hydrogencarbonate indicator reacts to oxygen?

it remains red

How does the hydrogencarbonate indicator reacts to carbon dioxide?

It changes colour, from red to yellow

How does limewater react to oxygen?

It remains colourless

How does limewater react to carbon dioxide?

It goes from colourless to milky

What happens to cobalt chloride paper when a drop of water is being added?

it changes colour from blue to pink

What are unreactive gases?

Nitrogen and noble gases

What is used to fill some food packages?

nitrogen

What is used to fill light bulbs?

argon

What is used to fill advertising lights?

neon

What is used to fill balloons and airships?

helium

Fill in the blanks: Plants make their own food by \___________________________________.

photosynthesis

What are the raw materials of photosynthesis?

carbon dioxide and water

What is the energy source of photosynthesis?

light energy absorbed by chlorophyll

What is the product of photosynthesis?

glucose

What is glucose that is not used immediately converted into?

starch

What is the by-product of photosynthesis?

oxygen

What happens when iodine solution is added to starch solution?

the colour changes from brown to dark blue

What happens when iodine solution is added to distilled water?

It remains brown

What's the purpose of putting the leaf in boiling water?

to destroy the cell membrane

What's the purpose of putting the leaf in hot alcohol?

to remove the chlorophyll from the leaf

What's the purpose of washing the leaf in hot water?

to remove the alcohol and make the leaf soft

What's the purpose of adding iodine solution to the leaf?

to test for the presence of starch in the leaf

What colour does a leaf turn into when iodine solution is added and when starch is presence?

dark blue

Fill in the blanks: \__________________ and \___________________ are produced during photosynthesis.

starch and oxygen