MODULE 3 PART 1.1

1. Matter.








Question Number. 1. An atom with 3 free electrons in its outer shell is said to be.



Option A. pentavalent.



Option B. covalent.



Option C. trivalent.



Correct Answer is. trivalent.



Explanation. Number of electrons in the outer shell is called the valency - 1 = monovalent, 2 = divalent, 3 = trivalent etc.













Question Number. 2. What is the mass number of an element?.



Option A. Number of electrons and protons.



Option B. Number of neutrons and protons.



Option C. Number of electrons and neutrons.



Correct Answer is. Number of neutrons and protons.



Explanation. NIL.













Question Number. 3. What do you get when you add 2H2 and O?.



Option A. H2 O.



Option B. 2H2 O.



Option C. 2H2 O2 .



Correct Answer is. 2H2 O.



Explanation. Water is molecules each made up of 2 hydrogen atoms and 1 oxygen atom. Here ther is 4 hydrogen atoms, and 2 oxygen atoms, so we can make 2 water molecules.













Question Number. 4. The splitting of a chemical compound is called.



Option A. bombardment.



Option B. synthesis.



Option C. analysis.



Correct Answer is. analysis.



Explanation. NIL.













Question Number. 5. What is the atomic number of an element?.



Option A. The number of neutrons in the atom.



Option B. The number of electrons in the atom.



Option C. The number of protons in the atom.



Correct Answer is. The number of protons in the atom.



Explanation. NIL. http://en.wikipedia.org/wiki/Atomic_number













Question Number. 6. An atom with 5 free electrons is said to be.



Option A. pentavalet.



Option B. covalent.



Option C. trivalent.



Correct Answer is. trivalent.



Explanation. The valency is the number of electrons in the outer shell if that number is 4 or less. If there are more than 4 electrons, the valency is 8 minus the number of electrons. In this case 8 -5 = 3 = trivalent.













Question Number. 7. An atom consists of.



Option A. protons, neutron and electrons.



Option B. protons and electrons.



Option C. protons and neutrons.



Correct Answer is. protons, neutron and electrons.



Explanation. NIL.













Question Number. 8. The maximum number of electrons in the inner shell of an atom is.



Option A. 8.



Option B. 2.



Option C. 4.



Correct Answer is. 2.



Explanation. NIL.













Question Number. 9. The mass of a proton equals the mass of a.



Option A. neutron.



Option B. beta particle.



Option C. electron.



Correct Answer is. neutron.



Explanation. Mass of a proton = mass of a neutron (well, very nearly).













Question Number. 10. Catalysts.



Option A. speed up reactions.



Option B. speed up and slow down reactions.



Option C. slow down reactions.



Correct Answer is. speed up reactions.



Explanation. A catalyst speeds up reactions, an inhibitor slows down reaction.