Iron rusts because
Iron is unstable
It is an intrinsic property of iron to rust
Iron reacts with the moisture present in the atmosphere
Iron metal is weak
Which of the following is not a reversible change ?
Heating of water to steam
Cooking of egg to scrambled eggs
Heating of wax to molter wax
Cooling a cake
Which of the following is the easiest to change ?
The colour of your hair
The shape of your face
The colour of your eyes
Both A & C
Forest fire is
A desirable change
A periodic change
An undesirable change
A physical change
The process of heating a liquid to a high temperature and rapidly cooling it to kill bacteria is called
Pasteurization
Chlorination
Bacterial infection
Sublimation
Air growth is a/an
Physical change
Chemical decomposition reaction
Irreversible reaction
Fast reaction
Rate of the reaction depends on:
Temperature
Concentration of the reactants
Presence of catalyst
All the above
If an atom or a group of atoms replace another atom or a group of atoms during a chemical change, then it is called:
Chemical combination reaction
Chemical displacement reaction
Photochemical reaction
As the concentration of reactants increases
Rate of the reaction decreases
Rate of the reaction increases
Rate of the reaction remains the same
Reaction stops
The making of a ring from gold is a ______ change and making a statue from wood is a _______ change
Irreversible, reversible
Reversible, irreversible
Irreversible, irreversible
Reversible, reversible
