Question

Question1.

Choose the correct answers from the following: [15]

I. The valency of aluminate radical is:

a) -1 b) -2 c) -3 d) -4

II. When lead nitrate is heated, it turns to:

a) Yellow solid b) Black solid c) Green solid c) Blue solid

III. Isotopes of an element have different physical properties because they have:

a) Different number of electrons. b) Different number of protons.

c) Different number of neutrons. d) Different number of nucleons.

IV. The position of calcium (Z=20) in the periodic table is:

a) Group1 and period 3 b) Group 2 and period 3

c) Group 1 and period 4 c) Group 2 and period 4

V. A radioactive isotope of an element used for the treatment of cancer is:

a) Carbon-14 b) Cobalt-60 c) Uranium-235 d) Iodine-131

VI. The number of valence electrons in

2− ion is:

a) 6 b) 4 c) 10 d) 8

VII. Rusting of iron is an example of:

a) Endothermic reaction b) Exothermic reaction

c) Photochemical reaction d) Decomposition reaction

VIII. The molecular formula of barium chlorate is:

a) BaClO4 b) BaClO3 c) Ba(ClO3)2 d) Ba(ClO)3

IX) The smallest atom of period 2 of the periodic table is:

a) Litnium b) Carbon c) Helium d) Fluorine

X. The valency of nitrogen in nitrogen dioxide is:

a) 4 b) 2 c) 1 d) 3

XI. Which of the following has no neutron in its nucleus?

a) protium c) Helium c) Deuterium d) Tritium

XII. The number of carbon atoms in hydrogen carbonate radical is :

a) 2 b) 1 c) 3 d) 4

XIII. The type of bonding in ammonia is:

a) Covalent d) Ionic c) Co-ionic d) None of these

XIV. Which of the following is an example of amphoteric oxide:

a) FeO b) Al2O3 c) MgO d) SiO2

XV. Which of the following is an example of anomalous pair in Mendeleeve’s periodic table:

a) Fe and Co b) Mn and Fe c) Co and Ni d) Mn and Co​

Answer 1

Answer:

these are too much give one by one.

$\huge\boxed{\mathfrak{\red{\fcolorbox{red}{pink}{ Hiii \: follow \: me }}}}$

Answer 2

Answer:

answer

I) -3

II)B) black solid

III) B) different no. of protons

IV) C) Group 2 and period 4

V)B) Cobalt-60

VI) a) 6

VII) D) Decomposition reaction

VIII) a) BaClO4

IX) d) Fluorine