science form 2 chapter 1-7

what is the unit for energy?

• newton

• joule

• force

• volt

• ampere

energy __________ be created and destroyed.

• can

• cannot

The air is made up of _____% Nitrogen.

• 87

• 78

• 76

How to test the presence of Oxygen?

• Use lime water

• Use glowing wooden splinter

• Use burning wooden splinter

• Use litmus paper

____________ helps in photosynthesis.

• Inert gas

• Oxygen

• Carbon dioxide

• Nitrogen

Plants absorb吸收 _________ and

releases释放 _________ during photosynthesis.

• Nitrogen , Carbon dioxide

• Oxygen, Carbon dioxide

• Nitrogen , Oxygen

• Carbon dioxide , Oxygen

• Carbon dioxide , Nitrogen

air is made of

• oxygen, hydrogen

• nitrogen

• carbon dioxide