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प्रश्न
An element A has 2 electrons in its fourth shell. State:
its valency
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उत्तर
Its valency is 2.
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संबंधित प्रश्न
Given below are some elements of the modern periodic table. Atomic number of the element is given in parentheses.
A(4), B(9), C(14), D(19), E(20)
(a) Select the element that has one electron in the outermost shell. Also, write the electronic configuration of this element.
(b) Which two elements amongst these belong to the same group? Give reasons for your answer.
(c) Which two elements amongst these belong to the same period? Which one of the two has bigger atomic radius?
Two elements ‘A’ and ‘B’ belong to the 3rd period of Modern periodic table and are in group 2 and 13, respectively. Compare their following characteristics in tabular form:-
(a) Number of electrons in their atoms
(b) Size of their atoms
(c) Their tendencies to lose electrons
(d) The formula of their oxides
(e) Their metallic character
(f) The formula of their chlorides
Write any one difference in the electronic configurations of group-1 and group-2 elements ?
Use the letters only written in the Periodic Table given below to answer the questions that Follow:

- State the number of valence electrons in atom J.
- Which element shown forms ions with a single negative charge?
- Which metallic element is more reactive than R?
- Which element has its electrons arranged in four shells?
The metal of Group 2 from top to bottom arc Be, Mg, Ca, Sr, and Ba.
1) Which one of these elements will form ions most readily and why?
2) State the common feature in the electronic configuration of all these elements.
What happens to the metallic character of the elements as we go down in a group of the periodic table?
How do electronic configurations of elements change in second period of periodic table with increase in atomic numbers?
Rewrite the following statement after correction, if necessary:
Elements in the same period have equal valency
Four elements P, Q, R and S belong to the third period of the Modern Periodic Table and have respectively 1, 3, 5 and 7 electrons in their outermost shells. Write the electronic configurations of Q and R and determine their valences. Write the molecular formula of the compound formed when P and S combine.
Atomic number of an element is 16. State
- the period to which it belongs
- the number of valence electrons
- whether it is a metal or non-metal
