Periodic Classification of Elements — Science STD 10 — Question

When water of mass 70 g and temperature 50 °C is added to water of mass 30 g, the maximum temperature of the mixture is found to be 41 °C. Find the temperature of water of mass 30 g before hot water was added to it.

Draw a neat labelled diagram : Mutation

How does the dispersion of white light take place when it passes through a glass prism?

Explain the meanings of the following symbols:

A solid element X has four electrons in the outermost shell of its atom. An allotrope Y of this element is used as a dry lubricant in machinery and also in making pencil leads.

1. What is element X?
2. Name the allotrope Y.
3. State whether allotrope Y is a good conductor or non-conductor of electricity.
4. Name one use of allotrope Y (other than lubrication and pencil leads)
5. Name two other allotropes of element X.

The non - metal A is an important constituent of our food and most of the fuels around us. A forms two oxides B and C. The oxide B is poisonous whereas oxide C causes global warming.

1. Identify A, B and C.
2. To which group of periodic table does A belong?
3. Name another element which is placed in the same group as A.

Explain the term corrosion with a suitable example.
(OR)
What is corrosion ?

A dentist’s mirror has a radius of curvature of 3cm. How far must it be placed from a small dental cavity to give a virtual image of the cavity that is magnified five times?

Draw a neat labelled diagram : Translation and Translocation

Complete the following table :

Type of the Satelite	Function of the satellite	The names of the Indian satellite series and their launch vehicles
(a) ____________	Fix the location of any place on the earth's surface	____________
(b) Weather satellite	____________	____________
(c) ____________	____________	IRS Launcher : PSLV