________ protects us from the harmful ultraviolet radiation.
Oxygen
Hydrogen
Fluorine
Ozone
__________ turns lime water milky.
Carbondioxide
Carbonmonoxide
Properties such as shape,size,colour and state of a substance are called its ________ properties.
Physical
Chemical
Thermal
Thermodynamic
Identify the substance that evaporates at room temperature:
Water
Oil
Kerosene
Ammonium chloride
Burning of wood is a _________ change.
Reversible
Temporary
A change in which a substance undergoes a change in its physical properties is called a ________ change.
Burning of Magnesium ribbon is a ________ change.
___________ is known as blue Vitriol.
Copper sulphate
Ferrous sulphate
Sulphuric acid
Zinc oxide
When liquids are heated, they turn into gases. The yellow egg yolk present inside the egg is a liquid but when it is heated, it changes into an omelet which is solid, why?
Sometimes, liquids turn into solids
Omelet does not follow the above rule
Strictly speaking, the rule does not apply to complex mixtures and egg yolk is a complex mixture
The given statement is false
A seed growing into a tree is an example of:
Slow physical change
Fast periodic change
Slow natural change
Man made reversible change
