Question

Why and how are elements arranged in 4th period?
Why the size of atom does not decrease regularly in a period?
Give the trend of ionization energy in a period.​

Answer 1

Answer:

• The reason for the arrangement of elements in the period is based upon the atomic number. In all periods, including the elements are arranged according to the atomic number in increasing order.
• It is because of the protons and electrons present in the atom of the elements. ... The size of the elements of one period increases due to increase in the number of protons.
• As you move across a period, first ionization energy increases. WHY? - As you move across a period, the atomic radius decreases, that is, the atom is smaller. Theouter electrons are closer to the nucleus and more strongly attracted to the center.