Which of the following substances is not a solid?

Which of the following properties is not characteristic of colloidal particles?

Which one of the following is not equal to gram molecular mass of hyderogen

The atomic number of neon (Ne), magnesium (Mg²⁺), aluminium (Al³⁺ ) and phosphorus (P^3-) are 10, 12, 13 and 15 respectively.Select the odd species in terms of electronic configuration.

Iodine solution is used to

One bone is joined with another bone by the tissue called

Whittaker classified all organisms into

A ball is thrown vertically upwards It rises to a height of 50 m and comes back to the thrower

When an object undergoes acceleration

10 kg wt is equal to

Ns is equivalent to

A tuning fork is vibrating in air. The number of compressions going past a given point per second is the

Antibiotic penicillin act against bacteria by

In large parts of India rains are mostly brought by the

Weed preventive measures are

Why is the rate of diffusion faster in gases.

Classify the following substance as elements, compounds or mixtures:
(i) Sodium,
(ii) hydrogen,
(iii) brass,
(iv) Carbon dioxide,
(v) Gunpowder,
(vi) Soda water,
(vii) Water,
(viii) Chlorine,
(ix) Air,
(x) Common salt,
(xi) Stainless steel,
(xii) iron fillings,
(xiii) oxygen
(xiv) Milk
(xv) blood,
(xvi) Ammonia,
(xvii) glass,
(xviii) pure marble,
(xix) emulsion,
(xx) wood,
(xxi) gold,
(xxii) Sugar.

What is meant by atomicity of an element?Give one example each of tetra-atomic and poly atomic elements.

A student weight 30kg.suppose his entire body is made up of electrons.How many electrons are there in his body?Compare the total number of electrons in his body with the population of India.

Differentiate between RER and SER.

What are characteristic structural features of meristematic cells?

Ram and his teacher were going through a park in a rainy season. Ram saw a small segmented animal creeping on the soil. Ram said to his teacher, sir, see here is baby snake. Let me kill it. Teacher stopped Ram and said it is not a snake. It is our friend, the earthworm that live in burrows in the soil.
Answer the following questions based on the above information:
(a) How can you say that it is not snake?
(b) How does an earthworm our friend?
(c) Give one reason to justify that teacher's action is environment friendly.

A cheetah is the fastest land animal and can achieve a peak velocity of 100 km/h upto distance less than 500m.If a cheetah spots his prey at a distance of 100 m, what is the minimum time it will take to get its prey,if the average velocity attained by it is 90 km/h.

A horse is pulling a cart.
(i) What is the force that causes the horse to move forward?
(ii) What is the force that causes the cart to move forward?

Give two points of difference between 'g' and 'G'.

The kinetic energy of an object of mass 'm' moving with a velocity of 5 ms^-1 is 25J.Calculate its kinetic energy when its velocity is doubled.

Derive a relation between wavelength, frequency and velocity of a wave.

conditions essential for good health and conditions essential for being free of disease. necessarily the same or different?Why?

List water pollutants.

What are the desirable agronomic characteristics for crop improvements?

What do you mean by diffusion? Explain giving an example.

Solubility of potassium nitrate at 313 K is 62 g. What mass of potassium nitrate would be needed to produce a saturated solution of KNO₃  in 50 g of water at 313 K what is the effect of change of temperature on the solubility of a salt?

In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid.The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g sodium ethanoate.Show that these observations are in agreement with the law of conservation of mass.
sodium carbonate + ethanoic acid \(\rightarrow \) sodium ethanoate + carbon dioxide + water

Compare all the proposed models of an atom given in this chapter.

(a) What would happen to the life of a cell there was no Golgi apparatus?

(b) Which cell organelle detoxifies poisons and drugs in the liver of vertebrates?

What is the difference between
(i) meristematic cells and permanent cells?
(ii) parenchyma and collenchyma?

What are phanerogams? How are they classified? Give example.

A car travels a certain distance with a speed of 50 km/h and returns with a speed of 40 km/h Calculate the average speed for the whole journey

The following is the distance-time table of an object in motion:

(a) What conclusion can you draw about the acceleration? Is it constant, increasing, decreasing, or zero?
(b) what do you infer about the forces acting on the object?

A ball is thrown upwards from the ground of a tower with a speed of 20 m/s. There is a window in the tower at the height of 15 m from the ground. How many times and when will the ball pass the window?
(Take, g = 10 m/s²)

(a) Define power.Write its SI unit.
(b) A freely falling object eventually stops on reaching the ground.What happens to its kinetic energy?

State some important characteristics of wave motion.

What are immediate cause and contributory cause of disease?

How addition of undesirable substances and change in temperature affect the water the life?

What are the three steps commonly used for the genetic improvement of various plants?

Give two reasons to justify:
(a) water at room temperature is a liquid.
(b) an iron almirah is a solid at room temperature.

Write three main difference between a mixture and a compound.

What is molecular formula? Explain with example what information can be derived from a molecular formula?

Give four characteristics of cathode rays

Water forms two-thirds of the weight of the body. Body cells contain about 60% to 70% of water.All life processes carried out in a cell require water medium.It is essential to well being, deprivation or loss of water, as in case of diaohrrea, dysentry, vomiting etc. is more immediately serious than of any other article in diet.On the basis of above information answer the following questions:
(i) What first aid you will provide to a patient who has lost sufficient water from the body cells due to loose motions?
(ii) How would you prepare the solution to hydrate the body cells of the patient?
(iii) What would you do for the community with this information?

What is the specific function of the cardiac muscle?

What is the advantage of using scientific names instead of common or popular names?

What is non-uniform motion? Give some examples.

(a) Express Newton's second law mathematically explaining the symbols used.
(b) Define SI unit of force from this expression.

A stone is dropped from the adge ofg the roof, find
(i) How long does it take to fall 4.9 m?
(ii) How fast does it move at the end of that fall?
(iii) How fast does it move at the end of 7.9 metres?
(iv) What is its acceleration after 1 s and after 2s?

A person holds a bundle of hay over his head for 30 minutes and get tried.Has he done some work or not?Justify your answer.

Define the terms time period and frequency of an oscillating body. Give their units and write the relation between them.

What are the immunisation programmes available at the nearest health centre in your locality?Which of these diseases are the major health problems in your area?

Is it necessary to replenish forests?

In large part of india most farmers use wells and tube wells for irrigation .There was a time when they used to dig very low to draw ground water.Now they have to dig more deep wells to tap water from the deeper strata and then lift water by pumps for iirrigation This is due to lowering of ground water level.Ground water level.Ground water is the rainwater that seeps through the soil and collects over non-porus rocks.
Think over the information given above and answer the following questions.
1. Why does ground water level is decreasing?
2. How can we recharge ground water level?
3. What can we do in this regard?

Distinguish, in tabular form, between solids, liquids and gases under the following characteristics:
(i) Intermolecular attraction
(ii) Density
(iii) Fluidity
(iv) Diffusion
(v) Kinetic energy of particles at a given temperature

(a) name the technique used to separate oil from water and also the principle involved in their separation.
(b) State what are saturated solutions.
(c) To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293 K.Find its concentration at this temperature.

(i) Define mole
(ii) How is related to Avogadro constant, relative mass and molecular mass?
(iii) What is the number of molecules in 0.25 moles of oxygen?Avogadro's no.= 6.022 x 10²³ 

Devise an experiment to demonstrate process of endosmosis and exosmosis. Draw diagram where is necessary.

A scotter starts from rest moves in a straight line with a constant acceleration and covers a distance of 64 m in 4s.
(i) Calculate its acceleration and its final velocity.
(ii) At what time the scooter had covered half the total distance?

(i) At some moment, two giant planets jupiter and saturn of the solar system are in the same line as seen from the earth. Find the total gravitational force due to them on a person of mass 50 kg on the earth. Could the force due to the planets be important?
Mass of the jupiter = 2 x 10²⁷ kg
Mass of the saturn = 6 x 10²⁶ kg
Distance of jupiter from the earth
= 6.3x 10¹¹ m
Distance of saturn from the earth
= 1.28 x 1012m
Gravitational constant,
G = 6.67 x 10^-11N -m² /kg²
Acceleration due to gravity on the earth
=9.8 m/s²
(ii) A bag of sugar weighs w at a certain place on the equator. If this bag is taken to Antarctica, then will it weigh the same or more or less. Give a reason for your answer.

Illustrate the law of conservation of energy by discussing the energy changes which occur when we draw a pendulum bob to one side and allow it to oscillate.Why does the bob eventually come to rest?What happens to its energy eventually? Is it a violation of the law of conservation of energy?