1) To find out number of neutrons in an atom, we need to know the a. atomic number b. proton number c. electron number d. mass number
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2) The attraction of two ions due to opposite charge is known as a. ionic bonding b. covalent bonding c. metallic bonding d. dative bonding
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3) To trace the path of phosphorus, the isotope of phosphorus which is added to the fertilizers, is a. Phosphorus-31 b. Phosphorus-32 c. Phosphorus-33 d. Phosphorus-34
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4) If the mass of protons and neutrons is 1, then the mass of electron is a. 2 b. 2-Jan c. 4-Jan d. 1/1890
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5) The name of physicist who discovered the nucleus of atom was a. Democritus b. John Dalton c. Ernest Rutherford d. Vander Waals
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6) Sodium ion has a. positive charge b. negative charge c. no charge d. may be positive or negative
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7) Radioactive particles give off a. waves b. rays c. energy d. light
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8) The formula that shows the number and kind of atoms which a substance of a molecule contained, is known as a. chemical formula b. atomic formula c. compound formula d. molecular formula
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9) Sodium becomes a cation when a. it loses a proton b. it gains a proton c. it loses an electron d. it gains an electron
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10) The symbol of potassium is a. Po b. K c. Ps d. Pa
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11) Electrons have a. negative charge b. positive charge c. no charge d. both charges
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12) As compare to ionic compounds, covalent bond has a. high melting but low boiling point b. low melting but high boiling point c. low melting and boiling point d. high melting and boiling point
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13) Ionic bonds are a. easy to break b. weak c. electrical bonds d. very difficult to break
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14) Valency of sodium is a. 1 b. 4 c. 3 d. 2
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15) Neutrons in an atom also affect the a. chemical properties b. physical properties c. bonding properties d. thermal properties
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16) Atoms of sodium and chlorine are stuck by chemical glue which is known as a. bond b. alpha gum c. force of glue d. atomic gum
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17) A large amount of heat is produced in power plants when energy is released which turns a. black rods into orange b. water into steam c. ice into water d. acid into alkali
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18) In nuclear power plants, energy is released a. quickly b. slowly c. normally d. very quickly
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19) The symbol of "Boron" is a. Bo b. C c. N d. Br
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20) The symbol of "Helium" is a. H b. He c. Na d. Hy
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