PART - 1 CH - 1 Chemical Reactions and Equations — Science STD 10 — Question

Define :
Endocrine gland

Define :
Meiosis

Why does an aqueous solution of an acid conduct electricity?

A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?

What can be said about the focal length of the eye lens if its curvature increases?

Write the positions of metallic, non-metallic and metalloid elements in the modern periodic table.

A current of 0.5 A is drawn by a filament of an electric butb for 10 minutes. Find the amount of electric charge that flows through the circuit.

What is the minimum number of rays required for locating the image formed by a concave mirror?

By which agents is cross-pollination achieved?