Combustion and Flame — Science STD 8 — Question

Name three types of substances in which an electric current can produce a chemical effect.

Name all the planets of the Solar System in the order of their increasing distances from the Sun.

Explain the difference between pure air and polluted air.

State the various uses of a periscope.

What are thermosetting plastics? Give two examples of thermosetting plastics.

Write two uses of bakelite.

For electroplating copper on an iron object, which terminal of the battery (positive or negative) is connected to the iron object? Also name the electrolyte you will use for this purpose.

We rarely see cases of smallpox or polio these days, but diseases like diabetes and heart problems are more common. Why?

Different between ‘endangered species’ and extinct species.

Explain why, an owl can see well in the night (but not during the day) whereas an eagle can see well during day (but not at night).