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Atoms and molecules Sample Test Paper

Class 09 Subject -Science Atoms and molecules Sample Test Paper
Time 1 hr  M.M.35
(Section A) 10 x 1 = 10
1. The atomic radius of hydrogen atom is
a. 0.037 nm b. 0.037 x 10 -9 m c. both a &b d. none
2. Complete the following sentence : In water, the proportion of hydrogen and oxygen is ---------- by mass
a. 1:8 b. 3:4 c. 9:0 d. none
3. The actual mass of hydrogen atom
a. 1.673 x 10 -24 g b. 1.673 x 10 c.1u d. both a & b
4. The symbol of cobalt a.C.o. b. CO c. Co. d. none
5. Atomicity of noble gases is one
a. True b. false c. can’t say d none
6. The molecular mass of sulfuric acid
a. 28 u b. 108 u c. 98u d. none
7. What are the number of electron and proton in chlorine ion
a. 17p & 18 e b. 18 p & 17 e c. 17 e & 0 e d. none
8. The value of symbol ‘L’ a. 6.022 x 10 23 b. 6.022 x 10 -23 c. 0.622 x 10 23 d. none
9. What is the mass of of 0.2 moles of oxygen atoms?
a. 2.3 g b. 3.2 g c. .32 g d. none
10. Write the atomicity of CO2 gas a. 2 b. 3 c. 0 d. none
(Section B) 10 X 1 = 10
1.what is meant by saying “the atomic mass of oxygen is 16? 
2. What is the significance of formula H2O?
3. Calculate the formula mass of calcium chloride and sodium carbonate
4. An element Z forms an oxide ZO3. What is the valency of Z?
5. Write the Latin names of sodium, iron, mercury and tin.
6. Define 1 u.
7. Define electro negativity of any atom.
8. Name the element represent by the following symbols Hg, Pb, Au, Ag and Sn
9. Write down the atomicity of carbon dioxide, oxygen, ozone, solid sulphur.
10. Write down the atomicity of carbon dioxide, oxygen, ozone, solid sulphur.
(Section C) 5 x 2 = 10
1. Write down the atomicity of carbon dioxide, oxygen, ozone, solid sulphur.
2. Give major draw –backs of Dalton’s atomic theory of matter.
3. Work out the formula of magnesium chloride.
4. The mass of a single atom of an element X is 2.65 x 10 -23g. What is its atomic mass? What could this element.
5. Calculate the molar mass of the following Ethyne and nitric acid
(Section D) 2 x 2.5 = 5
6. State the law of conservation of mass. Give one example also.
7. In an experiment, 1.288 g of copper oxide was obtained from 1.03 g of copper. In another experiment 3.672 g of copper oxide obtain from the 2.938 g of copper. Show that these figures verify the law of constant proportion.
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Comments

  1. Chemistry is the branch of science which deals with the properties, composition and structure of matter. Study of chemistry also includes the laws and principles related to the structure and inter-relations of elements and compounds.
    Chemistry has the task of investigating the materials of which our universe is made. Chemistry investigates chemical changes, conditions under which chemical changes occur. Chemistry also deals with the way in which similar changes can be brought about in laboratory and on a large scale in industries.
    Chemistry is a very vast field. Chemistry is divided into a number of branches such as Organic chemistry, Inorganic chemistry, Physical chemistry, biochemistry, Applied chemistry, Nuclear chemistry etc.

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