Oxygen

Oxygen percentage in Earth is.......

• 21%

• 78%

• 1%

Manganese dioxide is.........

• Making oxidation

• Making combustion

• A catalyst

Ozon layer is a layer consist of.....

• 1 atom of oxygen

• 2 atoms of oxygen

• 3 atoms of oxygen

We can use oxygen for mechanical ventilation in hospitals

• True

• False

Iron rusting is an example for......

• Combustion

• Preparing oxygen in laboratory

• Oxidation

.................... is saving the oxygen percentage in Earth

• Oxygen tanks

• Photosynthesis process

• Respiration system

Oxygen is colorless gas

• True

• False

The mass of burned object is............. the object before burning

• Less than

• Greater than

• Equal

Divers are using ...........

• Oxygen cylinder

• Ozone

• Nitrogen

Photosynthesis needs

• Sun, oxygen, water

• Sun, carbon dioxide, water

• Sun, food, water