EASY
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The total number of rare-earth elements is :

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Important Questions on Modern Periodic Table

MEDIUM

Consider the following radioactive decays

I. U92-α90Th and

II. 90Th-αRa88

In which case group of parent and daughter elements remains unchanged.

MEDIUM
To which group of the periodic table does an element having electronic configuration [Ar]3d54 s2 belong?
MEDIUM
The electronic configurations of bivalent europium and trivalent cerium are:
(atomic number: Xe=54 , Ce=58 , Eu=63)
EASY
An element of atomic number 118 would be a/an __________
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The last element of the p- block in 6th period is represented by the outermost electronic configuration:
EASY
Which of the following species is iso-electronic with Cr?
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The correct match among the following is

(a) Lithium, Sodium, Potassium            (i) Alkaline earth metals
(b) Beryllium, Magnesium, Calcium      (ii) Semi-metals
(c) Oxygen, Sulphur, Selenium             (iii) Alkali metaIs
(d) Silicon, Germanium, Arsenic           (iv) Chalcogens

EASY
The elements with atomic numbers 101 and 104 belong to, respectively:
MEDIUM
Among the given configurations, identify the element which doesn't belong to the same family as the others?
EASY
The 71st electron of an element X with an atomic number of 71 enters the orbital:
MEDIUM
The electron configuration of Fe3+ is (atomic number of Fe=26)
MEDIUM
The element with outer electronic configuration (n-1)d2ns2, where n=4, would belong to
EASY
Element "E" belongs to the period 4 and group 16 of the periodic table. The valence shell electron configuration of the element, which is just above "E" in the group is
EASY

Match the element in column I with that in column II.

  Column-I   Column-II
(a) Copper (p) Non-metal
(b) Fluorine (q) Transition metal
(c) Silicon (r) Lanthanoid
(d) Cerium (s) Metalloid

Identify the correct match :

EASY
The set that contains atomic numbers of only transition elements, is :
EASY
The element Z=114 has been discovered recently. It will belong to which of the following family/group and electronic configuration?
EASY
The electronic configurations of Eu (Atomic no. 63), Gd (Atomic no. 64) and Tb (Atomic no. 65) are: