What are the problems caused by the non-biodegradable wastes that we generate?
Non- biodegradable resources cannot be degraded or decomposed easily. And when they do not decompose they get accumulated and affect the environment.
Problems caused by the non- biodegradable wastes that is generated by us:-
When we use plastic bottles and plastic glasses, we throw them on the road, lakes, beaches instead of dustbins and they get accumulate and then pollute the environment. And, many types of pollutants are present which are non- biodegradable like radioactive substances, tins, glasses, electronic wastes etc all pollutes the environment which causes biomagnifications.
These pollutants when get accumulated in the environment and cause very serious diseases to the human beings and the animals.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
Outline a project which aims to find the dominant coat colour in dogs.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
How is the sex of the child determined in human beings?
(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
Calculate the number of electrons constituting one coulomb of charge.
What is an homologous series? Explain with an example.
Why is variation beneficial to the species but not necessarily for the individual?
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
Why is sodium kept immersed in kerosene oil?
Name two metals which are found in nature in the free state.
What is meant by power of accommodation of the eye?
List five things you have done over the last one week to —
(a) conserve our natural resources.
(b) increase the pressure on our natural resources.
Write the balanced chemical equations for the following reactions.
(a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water
(b) Zinc + Silver nitrate → Zinc nitrate + Silver
(c) Aluminium + Copper chloride → Aluminium chloride + Copper
(d) Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride
A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R′, then the ratio R/R′ is –
(a) 1/25 (b) 1/5 (c) 5 (d) 25
How is the small intestine designed to absorb digested food?
What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer.
(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.
Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?
What would you observe when zinc is added to a solution of iron(II) sulphate? Write the chemical reaction that takes place.