Periodic Classification of Elements — Science STD 10 — Question

What does CNS stand for? Which part of CNS:

1. Consists of two cerebral hemispheres, and
2. Has spinal nerves attached to it?

Solar cells are used to provide the electric current to charge the batteries of a car driven by an electric motor. Describe the energy changes which take place.

A student prepared solutions of (i) an acid and (ii) a base in two separate beakers. She forgot to label the solutions and litmus paper is not available in the laboratory. Since both the solutions are colourless, how will she distinguish between the two?

What will you observe when dilute ethanoic acid and dilute hydrochloric acid are put on universal indicator paper, one by one? What does it show?

Name the substance which is present in the blood, but not in the urine of a healthy person?

How are general growth and sexual maturation different from each other?

Write the balanced chemical equation for the following reaction and identify the type of reaction.
Magnesium ribbon is burnt in an atmosphere of nitrogen gas to form solid magnesium nitride.

Define the unit of electric current (or Define ampere).

Water helps in separation of oppositely charged ions from their ionic compound. Give reason.

Explain why carbon generally forms compounds by covalent bonds.