Question 1 :
State true or false. The greenhouse effect is a process that occurs when gases in Earth's atmosphere trap the Sun's heat.
Question 3 :
Oxygen is found in the elemental form in the atmosphere to the extent of 21%. TRUE OR FALSE?
Question 7 :
Carbon is incorporated into life-forms through the basic process of photosynthesis which is performed in the presence of Sunlight by all life-forms that contain chlorophyll.TRUE OR FALSE?
Question 10 :
An increase in the carbon dioxide content in the atmosphere would cause more heat to be retained by the atmosphere and lead to global warming.TRUE OR FALSE?
Question 12 :
In combined form, oxygen occurs as ____ in the Earth's crust and also in the air.
Question 15 :
In the crust,oxygen is found as the oxides of most metals and silicon, and also as carbonate, sulphate, nitrate and other minerals.TRUE OR FALSE?
Question 16 :
The process of nitrogen-fixing by bacteria does not take place in the presence of oxygen.
TRUE OR FALSE?
Question 19 :
Which of the following are biologically important compounds that contain both oxygen and nitrogen?
Question 22 :
The life-supporting zone of the Earth where the atmosphere, the hydrosphere and the lithosphere interact and make life possible, is known as?
Question 26 :
Carbon occurs in the combined state as _______ in the atmosphere.
Question 29 :
The endoskeletons and exoskeletons of various animals are formed from carbonate salts.TRUE OR FALSE?
Question 30 :
We need not to conserve our natural resources and use them in a sustainable manner. True or False?
Question 34 :
Calculate the number of molecules of sulphur ($S_8$) present in 16 g of solid sulphur.
Question 41 :
When 3.0 g of carbon is burnt in 8.0 g of oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.0 g of oxygen?
Question 43 :
Formula of sodium carbonate is ______ and that of ammonium sulphate is ______.
Question 44 :
Compute the ratio by mass of the combining elements for Ammonia.
Question 46 :
What is the metal which exists in the liquid state at room temperature?
Question 48 :
Compute the ratio by mass of the combining elements for Hydrogen chloride.
Question 50 :
Hydrogen and oxygen combine in the ratio of 1 : 8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?
Question 53 :
Which has more number of atoms, 100 g of sodium or 100 g of iron?
Question 59 :
What is an element which forms rust on exposure to moist air?
Question 60 :
What is the SI prefix for $10^{-12}$ multiples and submultiples of a unit?
