Question

Which of the following shows the correct prediction the pattern in the size of atoms (atom radii) from left to right across the periodic table of the elements.

The size of atoms will decrease from left to right because the increasing number of protons results in a greater pull on the electrons toward the nucleus.


The size of atoms will increase from left to right because the increasing number of electrons tends to overcome the pull of the protons and increase the size of their orbitals.


The size of atoms will increase from left to right because the increasing number of electrons occupy more space creating a larger atom.


The size of atoms will decrease from left to right because the increasing number of electrons are adding mass to the outside which is pulled toward the center.

Answer 1

The size of atoms will decrease from left to right because the increasing number of protons results in a greater pull on the electrons toward the nucleus.

Step-by-step explanation:

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons.

This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.

Thus option A is correct.