When iron reacts to form rust, what does it react with? Select all that apply.

• Nitrogen

• Oxygen

• Water

• Carbon dioxide

What is the substance present in hand warmers that react with air to warm the hands during winter?

• Copper powder

• sodium

• iron fillings

• Salt

Reaction of food with oxygen can cause it to go bad. How to prevent this?

• Add antioxidant

• Add sugar or salt

• Cook it throughly

• add more fats

what are the reactants in respiration? Select all that apply.

• Glucose

• water

• carbon dioxide

• oxygen

Photosynthesis and Respiration both occur in plants.

• True

• False

Combustion and burning are the same reaction.

• True

• False

Light energy is released during combustion, not burning.

• True

• False

How do we prevent iron objects from rusting? Select all that apply.

• Paint it

• Use an alloy of iron instead of pure iron

• plate it with chromium

• galvanize with zinc

Did you understand this topic clearly and fully?

• Yes Yes Yes!

• Hmmm Not so, still confused

• I understand nothing!