a Compare the electron configurations and atomic radii of ru

(a) Compare the electron configurations and atomic radii of rubidium and silver (see Figure 7.6 above or in your text). (Use the appropriate noble-gas inner-core abbreviation and the indicated format, for example [Ar]4s1 3d5 for [Ar]4s13d5.) Rb electron configuration, atomic radius, Ag electron configuration, atomic radius

Solution

Atomic number of Rubidium =37

Rubidium electron configurations: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s¹

we can write it like [Kr ] 5s¹

because Kr = 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶

Atomic number of Silver =47

Rubidium electron configurations: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s¹4d¹⁰

we can write it like [Kr ] 4d¹⁰5s¹

because Kr = 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶

Atomic radii of Silver is grater than the atomic radii of Rubidium.

R_Ag = 172 picometer

R_Rb = 248 picometer

Reason:

The atomic radii decrease across the Periodic Table because as the atomic number increases, thenumber of protons increases across the period, but the extra electrons are only added to the same quantum shell. As a result, the electron cloud contracts and the atomic radius decrease.