A freely falling object eventually stops on reaching the ground.What happens to its kinetic energy?

Water is a compound and not a mixture. List two reasons to justify your answer.

(a) define an element.
(b) Name a non-metallic element found in
(i) liquid,
(ii) gaseous state
(c) Pick metalloids from the following: Carbon, Silicon, Phosphorus, Gold.
(d) Which two properties of metals enable us to get the desired shape to metals?
(e) Name a metal which liquid at room temperature.

Calculate the number of atoms in one grame of zinc (atomic mass of zinc is 65.37).Give the weight of 1 atom of zinc.

What is a proton?What are its characteristics?

Differentiate between diffusion and Osmosis.

Define the following:
(a) Radial symmetry
(b) Bilateral symmetry

In everyday life, we see some objects at rest and others in motion. Birds fly, fish swim, blood flows through veins and arteries and cars move. We often perceive an object to be in motion when its position changes with time. However, there are situations where the motion is inferred through indirect evidences. For example, we infer the motion of air by observing the movement of dust and the movement of leaves of branches of trees.
(a) Define the term rest.
(b) Define the term motion.
(c) Give an example of directly perceivable motion.
(d) Give an example of indirectly perceivable motion.

(a) State two factors on which the gravitational force between two objects depends.
(b) Write the formula to find the magnitude of the gravitational force between the earth and an object on the surface of the earth.

Calculate the average density of the earth in terms of g, G and R.

During an experiment, on measurement of loss in weight of solid in tap water and salty water, when will be the maximum loss in weight  of the solid observed?

A man drops a 10 kg rock from the top of a 20 m ladder.What will be its kinetic energy when its reaches the ground? What will be its speed just before it hits the ground?Does the speed depend on the mass of the rock?

The human heart does 1.5J of work in every beat. How many times per minute does it beat, if its power is 2 W?

The speed of sound through a medium mainly depends on two factors: nature of the medium and its temperature .Sound travels fastest through solids and slowest through gases.This is because the elasticity of solids is much greater than that of liquids which,in turn,is greater than that of gases.
Answer the following questions based on the above information:
(a) In which of three media: air,water or iron,does the sound travel the fastest at a particular temperature?
(b) Why do we hear the horn of approaching car before the car reaches us?
(c) Why is the flash of lightning from clouds seen much before the thunder,although both occur simultaneously?

State in brief the role of photosynthesis and respiration in carbon-cycle and oxyen in nature.

What do you mean by vermicompost?

Define and explain the term: mixture.

A mixture is a combination of two or more substances that are not chemically united and do not exist in fixed proportions to each other.It can be physically separated into pure compounds or elements.Suppose you have a mixture of water, oil, iron filings and sulphur.
What steps you will take to separate the constituents of this mixture which are compounds and which are elements.

Which amongest the following has more number of atoms, 11.5 g of sodium or 15 g of calcium?How?(Given atomic mass of Na =23, ca=40)

What are the differences between animals belonging to the Aves group and those in the mammalia group?

What are unbalanced forces? Give examples.

A ball thrown up vertically returns to the thrower after 6 s. Find
(a) the velocity with which it was thrown up,
(b) the maximum height it reaches, and
(c) its position after 4 s.

List the measure for preventing infectious diseases.

Mention any four desirable traits for which new varieties are produced?

(i) A battery lights a bulb.Describe the energy changes involved in the process.
(ii) Calculate the amount of work needed to stop a car of 500 kg moving at a speed of 36 kmh^-1.