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प्रश्न
Use the letters only written in the Periodic Table given below to answer the questions that follow:
(a) State the number of valence electrons in the atom J.(b) Which element shown forms ions with a single negative charge?
(c) Which Metallic element is more reactive than R?
(d) Which element has its electrons arranged in four shells?
उत्तर
(a) The element J is placed in the 5th group; hence, its number of valence electrons is 5.
(b) The element M which is placed in the 7th group has 7 valence electrons and will gain only one electron to complete its octet; hence, element M will show a single negative charge.
(c) Element T is more reactive than element R because chemical reactivity increases down the group.
(d) Only element T is placed in the 4th period; hence, its electrons are arranged in four shells.
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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 do the valency and the atomic size of the elements vary while going from left to right along a period in the modern periodic table?
How does the valency of elements vary in going down a group of the periodic table?
Rewrite the following statement after correction, if necessary:
Elements in the same period have equal valency
Fill in the blank in the following statement:
On moving form right to left in the second period, the number of valency electrons ...............
How does the electropositive character of elements change on going down in a group of the periodic table?
How do the following change on moving from left to right in a period of the periodic table?
Give examples in support of your answer.
atomic structure (electron arrangements) ?
Chorine in the periodic table is surrounded by the elements with atomic number 9, 16, 18 and 35.
Which is more electronegative than chlorine?
What is modern periodic law?
Name or state following with reference to the element of the first three periods of the periodic table.
A metal in period 3 having valency 3.
