Combustion and flame

A chemical process in which a substance reacts with __________ to give off heat is called combustion.

oxygen

The substances which undergo combustion are known as __________ substances.

combustible

When combustion occurs rapidly, it is called __________ combustion.

rapid

The type of combustion in which material suddenly bursts into flames is called __________ combustion.

spontaneous

When a sudden reaction takes place with the release of heat and light, it is called an __________.

explosion

The minimum temperature to which a combustible substance must be heated to catch fire is called its __________ temperature.

ignition

The ignition temperature of __________ is 35 °C.

phosphorus

A fire extinguisher cuts off the supply of air or brings down the temperature of the __________.

fuel

Carbon dioxide comes out with a stream of liquid water at high pressure in a __________ fire extinguisher.

soda-acid

Water puts off the fire by cooling the combustible material below its __________ temperature.

ignition

In a flame, the dark inner zone surrounding the wick shows __________, indicating no burning.

darkness

The luminous zone of a flame produces a brilliant yellow __________ flame.

luminous

The outermost zone of a flame is the hottest part where complete __________ of the fuel occurs.

oxidation

Fuels should be cheap and readily __________.

available

A good fuel should produce a very small amount of __________ such as ash.

residues

On the basis of physical state, fuels are classified into solid, liquid, and __________ fuels.

gaseous

Solid fuels are those that occur in a solid state at __________ temperature.

room

The amount of heat energy produced by burning one kilogram of fuel is called the __________ value of the fuel.

calorific

Burning of coal and diesel releases __________ gas, which is a suffocating and corrosive gas.

sulphur dioxide

Carbon monoxide is a toxic air pollutant produced largely from vehicle __________.

emissions

Incomplete combustion of fuel releases many __________ gases such as carbon monoxide.

poisonous

Combustion of fuels can cause the rise in the temperature of the atmosphere, known as __________ warming.

global

Fuels like wood and coal produce unburnt carbon particles which can cause __________ diseases.

respiratory

The combustion of coal and diesel generates __________ dioxide, which can be deadly in poorly ventilated rooms.

sulphur

Fuels that occur in a liquid state at room temperature are known as __________ fuels.

liquid

Combustion of fuels releases gaseous oxides of __________, causing environmental pollution.

nitrogen

A characteristic of a good fuel is that it should not produce gases that __________ the air.

pollute

Combustible substances cannot catch fire unless their temperature is above their __________ temperature.

ignition

The combustion of fuels contributes to the formation of __________ rain, which is harmful to the environment.

acid

Hydrogen burns in the luminous zone combining with oxygen to form __________ vapour.

water

Burning of __________, coal, and petroleum can lead to the release of unburnt carbon particles.

wood

A good fuel should be __________ to store and handle safely.

easy