Expansion and contraction is done by
heating
mixing
cooling
both heating and cooling
When water freezes, it undergoes.
a physical change
a chemical change
vaporization
sublimation
Which of the following is a physical change ?
Melting of ice
Melting of wax
Formation of steam from water
All of these
A chemical change is also known as
Physical reaction
Nuclear reaction
Chemical reaction
None of these
Which one of the following is a reversible change?
Ripening of fruits
Curdling of milk
Folding of paper
Burning of paper
Expansion is shown by
a piece of paper
a piece of iron
a piece of cotton
all of the above
The changing of the solid directly into vapors on heating and vapors into solid on cooling.
Evaporation
Sublimation
Condensation
Radiation
Sublimation of iodine is an example of ______ change .
physical
chemical
exothermic
none of these
Tearing of paper is a
physical change
chemical change
irreversible change
none of these changes
Which one of the following is NOT a physical change?
Mixing salt and pepper
Mixing salt and water
Mixing sugar and water
Mixing sand and iron nails
