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प्रश्न
Name or state following with reference to the element of the first three periods of the periodic table.
A non-metal in period 2 having electronic configuration 2, 6.
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उत्तर
O [Oxygen]
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संबंधित प्रश्न
The position of eight elements in the Modern Periodic Table is given below where atomic numbers of elements are given in the parenthesis.
| Period No. | ||
| 2 | Li(3) | Be(4) |
| 3 | Na(11) | Mg(12) |
| 4 | K(19) | Ca(20) |
| 5 | Rb(37) | Sr(38) |
(i) Write the electronic configuration of Ca.
(ii) Predict the number of valence electrons in Rb.
(iii) What is the number of shells in Sr?
(iv) Predict whether K is a metal or a non – metal.
(v) Which one of these elements has the largest atom in size?
(vi) Arrange Be, Ca, Mg and Rb in the increasing order of the size of their respective atoms.
How many groups and periods are there in the modern periodic table?
How do the atomic size and metallic character of elements vary as we move :-
(a) down a group and
(b) from left to right in a period
Choose the most appropriate answer of the following:
Which of the following would weigh the least?
(A) 2-gram atoms of Nitrogen.
(B) 1mole of Silver
(C) 22.4 liters of oxygen gas at 1 atmospheric pressure and 273K
(D) 6.02 x 1023 atoms of carbon.
[Atomic masses: Ag=108, N=14, O=16, C=12]
Which of the following element would lose an electron easily?
(a) Mg
(b) Na
(c) K
(d) Ca
An element A has atomic number 14. To which period does this element belong and how many elements are there in this period.
An element X belong to 4th period and 17th group, state.
no of valence electrons in it
Name the non-metals present in period 2 and metals in period 3.
An element A has 2 electrons in its fourth shell. State:
is it a metal or non-metal
There are three elements E, F, G with atomic numbers 19, 8 and 17 respectively.
Classify the above elements as metals and non-metals.
