Question

what is a flame? what type of substances,on burning. give a flame?

Answer 1

Flame is a body of gas produced when a substance is heated. Combustible substances produce flame and incombustile substances doesn't produce flame. for e.g. kerosene, CNG produces flame and coal doesn't produce flame.
I hope this will help you

Answer 2

heya,

<> what is flame? 
A hot glowing body of gas that is generate fire is called flame. 
there are 3 zone of flame. these are
- outermost zone.
- middle zone.
- innermost zone.

<> what type of substances on burning?
some of the substance which burn by producing flame are kerosene oil, LPG, CNG, biogas, etc...

charcoal is a solid fuel which doesn't vaporise on the heating so it doesn't burn by producing a flame. 
substance such as paper, wood, dry leaves catch fire easily. 

thank you, i hope this will helps you!