Periodic classification of elements Worksheet-1
A. Atomic weight B. Atomic number
C. Number of neutrons D. None of these
A. U B. Ra C. Pb D. Hg
A. Na–Ca B. Na–Cl C. Ca–Cl D. Cl–Br
A. Elements of first period and Elements of second period
B. Elements of second period and Elements of third period
C. Elements of third period and Elements of fourth period
D. All of these
A. P B. S C. F D. D
A. B and Si B. B and Al C. B and Ga D. B and C
A. Na, K, Rb B. Mg, S, As
C. Cl, Br, l D. P, S, As
A. A noble gas element B. A transition element
C. A halogen D. An alkali metal
A. 2, 8, 7 B. 2, 8, 8 C. 2, 8, 4 D. 2, 8, 2
A. Electronic configuration of the atom
B. Atomic weight of the atom
C. Physical property of an element
Explanation: U > Ra > Pb > Hg Out of the given atoms Uranium atom is the heaviest.
Explanation: Na – Cl. Both belong to III period.
Explanation: Elements of second and third period
Explanation: Kr has atomic no. 36 which is a noble gas and all noble gases belongs to p-block.
Explanation: According to Dobernier’s law of triads the atomic mass of the central element was nearly the arithmetic mean of atomic masses of other two elements.
Explanation: 2,8,2. ∵ The atom will loose electrons easily.