Which of the following substance has the lowest ignition temperature?

What is global warming? Name the gas whose increasing percentage in air is leading to global warming. State a harmful effect which can be caused by global warming.

Explain how, burning if fuels such as coal, petrol and diesel leads to acid rain. How is acid rain harmful?

One of the following is not a combustible substance. This one is:

Which of the following is not used in making matchsticks these days?