In which of the following case do you think the long-term effects on your health are likely to be most unpleasant?
• if you get jaundice,
• if you get lice,
• if you get acne.
Why?
Jaundice can cause long-term effects on our health. It is a chronic disease and it takes a long time to be cured. It does not spread rapidly, but it develops slowly over a period of time.
Convert into mole.
(a) 12 g of oxygen gas
(b) 20 g of water
(c) 22 g of carbon dioxide.
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?
Why is the atmosphere essential for life?
You find your mass to be 42 kg on a weighing machine. Is your mass more or less than 42 kg?
What happens to the force between two objects, if
(i) the mass of one object is doubled?
(ii) the distance between the objects is doubled and tripled?
(iii) the masses of both objects are doubled?
Why are we normally advised to take bland and nourishing food when we are sick?
Why is the weight of an object on the moon 1/6th its weight on the earth?
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?
A stone is released from the top of a tower of height 19.6 m. Calculate its final velocity.
List any three human activities that you think would lead to air pollution.
How would you choose between two characteristics to be used for developing a hierarchy in classification?
List any three human activities that you think would lead to air pollution.
Why are manure and fertilizers used in fields?
Convert into mole.
(a) 12 g of oxygen gas
(b) 20 g of water
(c) 22 g of carbon dioxide.
Write down the formulae of
(i) sodium oxide
(ii) aluminium chloride
(iii) sodium suphide
(iv) magnesium hydroxide
On what bases are plants and animals put into different categories?
Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?
What is pasturage and how is it related to honey production?
Draw a sketch of Bohr’s model of an atom with three shells.
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?