Answer is: a. Rubidium (Rb) is more reactive than strontium (Sr) because strontium atoms must lose more electrons.
The ionization energy (Ei) is the minimum amount of energy required to remove the valence electron, when element lose electrons, oxidation number of element grows (oxidation process).
Alkaline metals (group 1), in this example rubidium, have lowest ionizations energy and easy remove valence electrons (one electron), they are most reactive metals.
Earth alkaline metals (group 2), in this example strontium, have higher ionization energy than alkaline metals, because they have two valence electrons, they are less reactive.
Rubidium electron configuration: ₃₇Rb 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶5s¹; one valence electron is 5s¹ orbital.
Strontium electron configuration: ₃₈Sr 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁶5s²; two valence electrons is 5s² orbital.
The concentration of this acid in moles per litre : 17.41
<h3>Further explanation</h3>
Given
99.5% acetic acid
density=ρ=1.05 g/ml
Required
the concentration (mol/L)
Solution
99.5% dan density 1.05 g/ml (MW acetic acid = 60 g/mol)
Phosgene on reacting with <span>phenylmagnesium bromide generates
benzoyl chloride.
Since, </span>phenylmagnesium bromide is added in excess. It would further react with benzoyl chloride to form
benzophenone.
Benzophenone on further reacting with phenylmagnesium bromide, and aqueous treatment, gives
triphenylmethanol.
Entire reaction pathways is shown below: