Chemical Effects of Electric Current — Science STD 8 — Question

Explain why, the soles of our shoes wear out gradually.

How do you prevent the spread of communicable diseases ?

Name the substance which is needed continuously by thyroid gland to make thyroxine hormone.

Name the gas evolved when a metal reacts with water.

In which female reproductive organ does the embryo get embedded?

What happens when you apply a force on an inflated balloon by pressing it between your palms ?

Suggest a suitable word for the following statements. Agent which spreads pathogens from one place to another.

Paheli and Boojho observe a bright object in the night sky which was not twinkling. Paheli says, it is a star and Boojho says it is a planet. Who is correct?

In the following statements, the underlined words are jumbled up. Write them in their correct form. Vehicles produce high level of pollutants like carbon dioxide, nitrogen oxides, nobrac moondexi and mosek.

Name the unit used to measure the loudness of sound. Also write its symbol.