English Medium कक्षा १० - CBSE Question Bank Solutions for Science

The human body contains a large number of cells A which are very long and branched, and look like electric wires. The longest branch of this cell is B whereas there are many small branches C. Any two A cells do not join to one another completely in the human body. There is a microscopic gap D between every pair of adjacent A cells through which electric impulses can pass by the release of a chemical substance.
(a) What are cells A?
(b) What is the name of (i) branch B, and (ii) branches C?
(c) What is the microscopic gap D known as?
(d) What is the function of cells like A in the human body?
(e) The cells A are of three types. name the three types.

The organ A which is located inside the skull of our body is protected by a bony shell B. It is surrounded by three layers membranes C. The spaces between these layers are filled with a liquid D which protects organ A from mechanical shocks. Organ A in combination with another organ E makes up the central nervous system.

(a) What is organ A?
(b) What are B, C and D?
(c) Name the organ E.
(d) While walking barefoot, if we happen to step on a sharp piece of stone, we immediately lift our foot up. Which of the two organs: A or E, is directly involved in this action?
(e) If we step out from a darkened room into bright sunlight, we close our eyes for a moment. Which of the two organs: A or E, is directly involved in this action?

Explain why the tongue may be considered as both a receptor and an effector organ.

Why are metals called electropositive elements whereas non-metals are called electronegative elements?

State whether the following statement is true or false:
Non-metals react with dilute acids to produce a gas which burns with a 'pop' sound.

From amongst the metals sodium, calcium aluminium, copper and magnesium, name the metal:
(i) which reacts with water only on boiling, and
(ii) another which does not react even with steam.

What changes in the colour of iron nails and copper sulphate solution do you observe after keeping the iron nails dipped in copper sulphate solution for about 30 minutes?

What name is given to those metal oxides which show basic as well as acidic behaviour?

Name two metals which form amphoteric oxides.

A copper coin is kept immersed in a solution of silver nitrate for some time. What will happen to the coin and the colour of the solution?

Name the metal which has been placed at the bottom of the reactivity series.

Name the metal which has been placed at the top of the reactivity series.

Name the metal which has been placed just below copper in the reactivity series.

Which of the two metals is more reactive: copper or silver?

Write equation for the reaction of sodium with oxygen.

Write equation for the reaction of magnesium with oxygen.

What will happen if a strip of zinc is immersed in a solution of copper sulphate?

What will happen if a strip of copper is kept immersed in a solution of silver nitrate (AgNO₃)?

How would you show that silver is chemically less reactive than copper?

Give reason for the following:
Blue colour of copper sulphate solution is destroyed when iron filings are added to it.