Question

The effective nuclear charge of an element with three valence electrons is 2.60 what is the atomic number of elements

Answer 1

Effective nuclear charge: is the actual amount of positive (nuclear) charge experienced by an electron in a multi-electron atom.

• Effective nuclear charge 2.60 and valence shell contain 3 electrons.
• Thus, the minimum number of shells for the given element is two i.e (n=2) and its configuration will be $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^1$
• Thus, the given element has 5 electrons in all.
• Also, for a neutral atom, No. of electrons = Atomic number
• Thus, the atomic number of the element is 5.