Which of the following energy has revolutionized our lives but at the same time, it has an impact on the environment?
a) light energy of sun
b) energy obtained by burning of fossil fuels
c) hydro-electric energy
d) wind energy
Certain objects which are made of metals left in open decolour and develop rough edges. What type of this process is?
a) fermentation
b) sublimation
c) rusting
d) precipitation
Explanation:Rust is the term we use to describe red iron oxides produced when
ferrous metals corrode. Rust is the common name for the chemicals that result
when iron reacts with oxygen and water. “Rust” is poorly defined in chemistry,
however—lots of chemicals can be formed when iron is left exposed.
Which of the following metal can easily get rusted and tarnished in
air?
a) gold
b) silver
c) copper
d) iron
Which of the following gas is needed for rusting?
a) carbon dioxide
b) nitrogen
c) carbon monoxide
d) oxygen
What is the original color of iron before it gets rusted?
a) golden
b) black
c) silver
d) red
What is produced when iron gets rusted?
a) iron sulphide
b) iron oxide
c) iron chloride
d) iron hydroxide
