EDUCATION SPRINT
WORKSHEET Atoms & Molecules Roll No.
Student Name Class
Question 1 2 3 4 Marks Obtained Total Marks Signature of Examiner
Marks Obtained 40
section A () State if the following are true or false [6]
1. State whether the following statements are true or false: A chloride ion has negative charge
because it has more electrons than a neutral atom.
2. State whether the following statements are true or false: A sodium ion has positive charge
because it has more protons than a neutral atom.
3. The name of Li3 N is lithium nitrite.
4. One mole of sodium sulphate contains 2 atoms of Na, 1 atom of S, 4 atoms of oxygen.
5. State whether the following statements are true or false: A chloride ion has negative charge
because it has more electrons than a neutral atom.
6. State whether the following statements are true or false: A sodium ion has positive charge
because it has more protons than a neutral atom.
section A () Fill in the blank with correct answer [20]
7. Fill in the following blanks: A mole represents an ____________ number of particles of a
substance.
8. Matter can neither be created nor be destroyed is law of __________.
9. Fill in the following blanks: 64g of oxygen gas contains _________ Moles of oxygen atoms.
10. Fill in the blanks. The formula unit mass of Ca 3 (P04 )2 is _______.
11. The lightest element is ________.
12. Fill in the following blanks with suitable words: In water, the proportion of oxygen and
hydrogen is _________ by mass.
13. Fill in the following blanks: 60g of carbon element are ____________ moles of carbon atoms.
14. Fill in the following blanks: 1 mole contains __________ atoms, molecules or ions of a
substance.
15. Fill in the following blanks: 0.5 mole of calcium element has a mass of ____________.
16. Fill in the following blanks with suitable words: In a chemical reaction, the sum of the
masses of the reactants and the products remains unchanged. This is called _________.
17. Fill in the following blanks with suitable words: The particle which is formed by the gain of
electrons by an atom is called _________.
18. Fill in the following blanks with suitable words: The particle which is formed by the loss of
electrons by an atom is called _________.
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19. Fill in the following blanks with suitable words: A sulphide ion has negative charge because
it contains less ____________ than ____________.
20. Fill in the following blanks: A mole represents an ____________ number of particles of a
substance.
21. Fill in the following blanks with suitable words: The particle which is formed by the loss or
gain of electrons by an atom is called _________.
22. Fill in the following blanks: 64g of oxygen gas contains _________ Moles of oxygen atoms.
23. Fill in the following blanks with suitable words: In water, the proportion of oxygen and
hydrogen is _________ by mass.
24. Fill in the following blanks: 0.5 mole of calcium element has a mass of ____________.
25. Fill in the following blanks with suitable words: The particle which is formed by the gain of
electrons by an atom is called _________.
26. Fill in the following blanks with suitable words: The particle which is formed by the loss of
electrons by an atom is called _________.
section A () Do as directed [14]
27. Determine the molecular mass of ZnSO4 [atomic mass of Zn = 65u, S = 32u, 0 = 16u]
28. What name is given to the amount of substance containing this number of atoms?
29. Write the formula of the following compound: Magnesium sulphate.
30. Write down the formulae of. sodium oxide.
31. Write the atomicity of the following: Na 2 SO4
32. Define the following terms. Molecule.
33. An element X forms X2 (CO3 )3 type compound. What is the formula of its phosphate and
chloride?
34. Write down the formulae for the following compounds: Magnesium hydroxide
35. What do we call those particles which are formed: By the gain of electrons by atoms?
36. Name the scientist who gave atomic theory of matter.
37. Which particular atom of the above element is used for this purpose?
38. Give two symbols which have been derived from the “English names” of the elements.
39. How many molecules are present in one gram molecular mass of a substance?
40. If the valency of hydrogen is 1 and that of nitrogen is 3, work out the formula for ammonia.
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