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प्रश्न
Answer the following question.
Define the atomic size. Give its unit of measurement. In the modern periodic table what trend is observed in the atomic radius in a group and a period and why is it so?
उत्तर
Atomic size is the distance between the center of an atom i.e. from the nucleus to the outermost shell (valence shell) of that atom.
Atomic size is measured in Angstroms (A), where 1 Angstrom = 10-10 meters.
In the modern periodic table, the atomic size of elements increases down the group and the atomic size decrease along the period from left to right.
Down the group, as the number of energy shells of the atoms keeps on increasing from top to bottom so, the atomic radius also increases.
During the period, the atomic number of elements increases which leads to an increase in the number of protons inside the nucleus and thus, the effective nuclear charge increases. So, the atomic radius decreases over the period.
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संबंधित प्रश्न
Explain why, the noble gases are placed in a separate group.
The atomic particle whose number in the atoms of an element always remains the same and which forms the real basis for the modern classification of elements is:
(a) electron
(b) proton
(c) neutron
(d) meson
Which element has the electronic configuration 2, 8, 2?
State how the valency of elements varies in a group of the periodic table?
Name two elements in Alkali metals.
The electronic configuration of an element T is 2, 8, 8, 1.
What is the group number of T?
How will the tendency to gain electrons change as we go from left to right across a period? Why?
How were elements arranged in the long form of the periodic table or the Modern Periodic Table?
Choose an element from period 3 of modern periodic table that matches the description given below in instance. Give a reason for your choice.
It has a similar structure to diamond.
Spot the error:
The elements of group 13 are called the carbon family.
