Why Atomic size decreases as we go from left to right in Modern Periodic Table?

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Solution

Answer:
Increasing nuclear charge pulls the electrons closer to the nucleus.
Explanation:
Increasing nuclear charge pulls the electrons closer to the nucleus.

Now, assuming that this one sentence didn't actually make anything clearer, let's break this down:

Elements in the same period have electrons with roughly the same amount of energy.

As you move across a period from left to right, the elements have an increasing number of protons.

Protons pull electrons closer to the nucleus because positive and negative charges attract.

Because the electrons of all the elements in a period have the same amount of energy (i.e. they're pretty much equal) and an increasing number of protons gives the nucleus more "pulling power", the electrons are pulled more tightly to the nucleus. This makes the atom smaller.

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Similar questions

(a) How does the size of atoms (atomic size) generally vary in going from left to right in a period of the periodic table? Why does it vary this way?

(b) What happens to the metallic character of the elements as we move from left to right in a period of the periodic table?

Q. (a) Define the following terms
(i) Valency(ii) Atomic size
(b) 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?

Q. Why does the size of atom decreases as we go across a period?

Q. Assertion :Atomic size decreases in a period due to increase of atomic number. Reason: The nuclear charge is increasing and size of valence shell remains same as we move from left to right. Hence, in any period, the atomic size of the element decreases from left to right.

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

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