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

Hint: 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.