Burning
Trending Questions
- Formation of curd
- Cutting a tree
- Baking bread
- Making popsicles
Write True/False against the following statements and also correct the false statement.
(a) A physical process in which a substance reacts with oxygen to give off heat is called combustion
(b) Water is the best extinguisher for fires involving electrical equipment
(c) Alcohol, CNG and LPG are inflammable substances.
(d) Increased concentration of nitrogen in air is believed to cause global warming.
(e) Greater the calorific value, better is the fuel
(f) Middle zone is the hottest zone of a flame.
(g) The substances which vapourise during burning, give the flame
Which of the following is/are component(s) required for propagation of fire?
Heat
Oxygen
Fuel
Carbon Dioxide
- Formation of curd
- Baking bread
- Making popsicles
- Cutting a tree
Name the product formed when hydrogen burns in air with a pale blue flame.
Digestion of food is a physical change.
True
False
- Boiling of water - reversible change
- Growth of plants - irreversible change
- Rotting of apple - irreversible change
- Breaking of glass - reversible change
Which of the following is not a physical change?
Boiling of water to give water vapor
Melting of ice to give water
Dissolution of salt in water
Combustion of Liquified Petroleum Gas (LPG)
- lignite
- charcoal
- peat
- coal tar
- Making sand castle on beach
- Making egg omelette
- Burning of paper
- Cutting of trees
A small quantity of curd is added to warm milk. The milk is stirred and is set aside for few hours at a warm place. In a few hours, the curd is formed. This is an irreversible change because
Sometimes curd can be reverted back to milk and sometimes not.
Curd cannot be converted back to milk.
Curd can be converted back to milk.
No change is happening.
When we burn a candle, which of the following changes occur?
Physical Change
Chemical Change
Natural change
Periodic change
Classify the following change as physical or chemical change:
The lighting of an electric lamp.
Alex: Melting of ice is a chemical change.
Arya: Melting of ice is a physical change.
Alex
Arya
Is burning of paper a physical or chemical reaction?
- Growth of plants - irreversible change
- Breaking of glass - reversible change
- Boiling of water - reversible change
- Rotting of apple - irreversible change
- True
- False
- Inflating a ballon
- Shedding of leaves
- Ripening of fruit
- Bursting of a ballon
- Heating of iron
- Softening of iron
- Cooling it down
- Melting of iron
- Placing in mould
On placing an inverted tumbler over a burning candle, the flame extinguishes after some time. This is because of non availability of
(a) Oxygen
(b) Water vapours
(c) Carbon dioxide
(d) Was covered with tumbler
- Heat
- Oxygen
- Fuel
- Carbon Dioxide
- Cement
- Salt
- Sugar
- Oil
- Tearing of paper
- Freezing of water
- Melting of wax
- Bursting of balloon
- Softening of iron
- Melting of iron
- Placing in mould
- Cooling it down
- Heating of iron