Question

arrange these elements in the decreasing order of their atomic size: magnesium,chlorine,sodium,sulphur,silicon​

Answer 1

concept : atomic size increases when we go from top to bottom in a group. This is because major energy levels are being filled with more and more electrons. the electrons get further and further from the nucleus.

atomic size decreases when we go left to right in a period. this is because extra electrons are entering the same level while the nucleus gets larger and more positive. this draws the electron cloud in towards the nucleus.

here, magnesium,chlorine,sodium,sulphur,silicon are elements of third period.

first arrange in periodic table format.

i.e., sodium, magnesium, silicon, sulphur , chlorine.

so, arrangement of atomic size : sodium > magnesium > silicon > sulphur > chlorine

Answer 2

Answer:

Sodium >magnesium >silicon>sulphur>chlorine