Layers	Broilers
Layers are egg-laying birds, managements for the purpose of getting eggs	Broilers are maintained for getting meat
Layers start producing eggs at the age of 20 weeks. so they are kept for layer periods that depends upon laying period	They are raised upto 6-7 weeks in poultry farms and then sent to market to meat production
They require enough space and adequate lighting	they require conditions to grow fast and lown mortality
They require restricted and calculated feed with vitamins minerals and micronutrients	Their daily food requirments is rich in protein and vitamin-A and K.the fat content also should be adequate

(c) You are more likely to fall sick when your friend is suffering from measles. This is because measles is highly contagious and can easily spread through respiration i.e., through air. Thus, if your friend is suffering from measles, stay away from him otherwise you might easily get infected with the disease.

23 gram atomic unit or 23 gram sodium (1 mole) = 6.022 x 10²³ atoms
100 gram atomic unit or 100 gram sodium (1 mole) = \(\frac { 6.022\times { 10 }^{ 23 }\times 100 }{ 23 } =2.617\times { 10 }^{ 24 }\)atoms
again 56 gram atomic unit or 56 grams iron (1 mole) =  6.022 x 10²³ atoms
100 gram atomic unit or 100 grams iron = 1.075 x 10²³ atoms
Thus 100 g of carbon has more atoms than 100g of iron.

(i) 50+273=323K
(ii) Activity Take little amount of water in three containers which have different surface areas. Keep hem in sunlight for 2 h. Measure the volume of water left in all three containers.
Observation The amount of water left will be least in container having largest surface area among them.
Conclusion Greater the surface area, more will be the rate of evaporation.

(a) Matter
(b) Matter occupies space and mass
(c) matter is available to us solid, liquid or gas.
(d) Smell and love cannot be considered as matter as these are only feelings.You cannot assign any be mass or volume to a love or smell
(e) Trivial things can be significant.It should not be ignored.

Characteristics of particles matter are:
(i) Particles of matter have space between them
(ii) Particles of matter are continuously moving and thus possess kinetic energy.
(iii) Particles of matter can diffuse into one another.
(iv) Particles of matter attract each other.The force of attraction varies from one kind of matter to another.
(v) Particles of matter have mass.

Take a beaker half filled with water.Mark the level of water.Now add some matter like sugarm, salt or dettol in it.It will be observed that the added matter disappears and there is hardly and change in level of water.This is because particles of one matter, i.e., salt, sugar or dettol get into the sapces between the particles of the other matter, i.e., water.Thus we can say that there is enough between particles of matter.

Below a certain temperature, gases can be liquefied by increasing pressure.

The average kinetic energy of the particles of  aliquid increases as the temperature is raised.The temperature is expossed in Kelvin(K) scale in SI unit.The boiling point of water is 373K(\(100°C\) +273=373) .

Boiling point of a liquid increases with pressure.Because b. pt. is the temperature at which the pressure of the liquid becomes equal to the atmospheric pressure.Thus if the atmospheric pressure is increased, more heat will have to be given to make it equal to the existing pressure.Thus b. pt. increases with the pressure above the liquid.

Yes, generally liquids have lower density than solids.But in case of ice which is a solid, the structure of ice is such that there are vacant spaces between water molecules thus making ice together than water.Hence ice floats on water.

1.Composite manure
2.We can prepare compost in the following way:
Dig a pit, about 3 feet deep(or more as required) Add the biogradable garbage or leaves and other plant parts in to the pit.
3.Our duty is to educate farmers and gardeners the importance of compost manure and also about the method of preparing compost.

Based on the water sources of fish production, they are of following two types:
(i) Marine (oceanic) fisheries
(ii) Inland fisheries i.e., fresh water fisheries

(i) The animals basically domesticated for the milk production, are called milch animals.
(ii) Examples: Cows, buffaloes, goats and camels.

Maize - carbohydrate
green gram - proteins
ground nut - fats (fatty acids)
Niger - fats (fatty acids)

For eliminating polio, the vaccines are prepared from weakened infectious agent.These vaccines are in liquid form, usually called poliodrops.polio drops or preparations stimulate the body to produce antibodies against the polio virus and make body immune to the polio disease.As polio virus affects children, campaigns are organised to provide polio drops periodically to children under 5 years of age.

(i) Community health includes all those activities which individually between themselves contribute to the improvement of the community.
(ii) Community health comprises all efforts for maintaining, protecting and improving the health of the people. 

(i)  Jellyfish     - Phylum Coelenterata
(ii) Earthworm - Phylum Annelida
(iii) Cockroach - Phylum Arthropoda
(iv) Rat            - Phylum Vertebrata Class-Mammalia

(a) Atoms
(b) United we stand, divided we fall. Being together we can hope to achieve great heights.

(i) Molecular mass of water (H₂O)
= 1 x 2 + 16 = 18u
:. Number of moles in 20 g of water =\(\frac { 20 }{ 18 } \)
(ii) 44 gm of carbon dioxide = 1 mole
22 gm of carbon dioxide = 0.5 mole

(a) Quick lime - Calcium and oxygen
(b) Hydrogen bromide - Hydrogen and bromine
(c) Baking powder - Sodium, Hydrogen, Carbon and oxygen
(d) Potassium sulphate - Potassium, Sulphur and oxygen

(a) 24 g of Mg = 6.022 x 10²³ particles
48 g of Mg =  12.044 x 10²³ particles
(b) 32 g of O₂ = 6.022 x 10²³ particles
8 g of O = 1.50 x 10²³ particles
(c) 1 mole of carbon = 6.022 x 10²³ particles
0.1 mole of carbon = 6.022 x 10²³ particles

The chemical formula of a compound is the symbolic representation of its composition.It gives the number and kinds of atoms which are chemically united in a given compound.For example, the chemical formula of hydrogen sulphide is HS.It tells that in hydrogen sulphide two hydrogen atoms and one sulphur atom are chemically united.

An atom is a building block of an element.It is very very small, so small that millions of atoms when stacked would hardly make a layer as thick as thin sheet of paper.The radius of an atom of hydrogen is 10^-10 m or 10^-1 nm, one molecule of water is 1 nm.Compared to it grain of sand is 10^-4 m.

(i) 1 Mole of Carbon atom = 6.022 x 10²³ atoms
6.022 x 10²³ atoms of carbon weigh = 12 g
1 atom of carbon weighs = \(\frac { 12 }{ 6.022\times { 10 }^{ 23 } } \\ \)  
= 1.99 x 10^-23
(ii) (a) n = 0.5 mol; M = 14 x 2 = 28 g; m = ?
m = n x M = 0.5 x 28 = 14.0 g
(b) n = 0.2 mol; M = 16 g; m = ?
m = n x M = 0.2 x 16 = 3.2 g
(c) n = 4 mol; M = 27 g; m = ?
m = n x M = 4 x 27 = 108 g