Question

Electropositivity, density and atomic radii of alkali metals increase down the group. Explain.

Answer 1

With an increase in the element serial number, i.e. by the charge of the nucleus - (the number of protons and electrons) the radius of atoms increases, the density, the ionization energy, the relative electronegativity and electron affinity naturally decrease, the reduction and metal properties increase. The farther the electrons from the nucleus, the weaker they are attracted to it, the easier this atom gives away electrons. And this means that the metallic properties are more pronounced, the farther the valence electrons from the nucleus (ceteris paribus). Therefore, from top to bottom, the number of energy levels in atoms increases, the metal activity of elements increases, i.e., the ability of atoms to donate electrons.Therefore, the atomic radius, density and electropositivity increase.