Question

The following chemical compound $CsB{{r}_{3}}$ contains?
A) $Cs-Br$ covalent bonds
B) $C{{s}^{3+}}$ and $B{{r}^{-}}$ ions
C) $C{{s}^{+}}$ and $Br_{3}^{-}$ ions
D) $C{{s}^{3+}}$ and $Br_{3}^{3-}$ ions

Answer 1

Properties of group $1$ element (Alkali Earth Metals) and element and group $17$ element (Halogen family) on the basis of having a single electron in its outermost energy level as a donor and acceptor vice versa. The given compound exhibits an Ionic sharing of bonds in between them.

Complete step-by-step answer:
i) Cesium $Cs$ is a group $1$ element that means it has $1+$ electrons in its outer orbit.
That results $Cs$ is donor group and it will acquire $+$ sign by giving its $1$ electron to adjacent element i.e. $C{{s}^{+}}$
ii) Similarly, Bromide $Br$ is a group $17$ element which possesses the property and has $+7$ or $-1$ electrons in their outermost orbit.
Which will result in formation of $B{{r}_{3}}^{-}$ it can either lose it’s $7$ or gain, as group $17$ elements are electrons acceptor they all acquire a negative sign. Also here 3 molecules of bromine is used which results $B{{r}_{3}}^{-}$
iii) Therefore the chemical compound $CsB{{r}_{3}}$ contains $C{{s}^{+}}$ and $B{{r}_{3}}^{-}$ ions.

Addition Information:
i) Cesium belongs to the group $1$ of alkali metals. These groups of elements are characterized on the basis of having a single electron in its outermost energy level and have a tendency to lose it, thus forming a mono positive ion.
ii) This tendency of alkali metals such as Lithium$(Li)$, Sodium $(Na)$, Potassium $(K)$ , Rubidium $(Ru)$, Cesium $(Cs)$ and Francium $(Fr)$ is due to their low ionization energy and low electron affinity.
iii) A bromide is a chemical compound containing a bromide ion or ligand. This is a bromine atom with an ionic charge of $-1(Br)$

Thus, the correct answer is Option (C) $C{{s}^{+}}$ and $B{{r}_{3}}^{-}$ ions.

Note:
i) Cesium bromide $CsB{{r}_{3}}$ is an ionic compound, and can further be classified as a salt
ii) Usually a bond between a metal and a nonmetal is ionic.
iii) Cesium is a metal and bromine is a nonmetal. In addition, we can look at the difference in electronegativity between the two elements.
iv) Electronegativity $(EN)$ is the tendency of an atom to attract electrons to itself. Metals tend to have lower electronegativity than nonmetals.