Question

Use the periodic table to answer the following questions.
(a) Identify an element with five electrons in the outer subshell.
(b) Identify an element that would tend to lose two electrons.
(c) Identify an element that would tend to gain two electrons.
(d) Identify the group having metal, non-metal, liquid as well as gas at the room temperature.

Answer 1

Elements with five electrons in their outermost shell should have the electronic configuration of $n{{s}^{2}}n{{p}^{5}}$. Elements generally tend to lose or gain electrons to attain the stable noble gas electronic configuration. Halogen families have metals , non-metals, liquid as well as gases at room temperature.

Complete step by step answer:
Let us discuss each condition one by one,
(a) Identify an element with five electrons in the outer subshell.
Elements which have five electrons in their outer subshell should have the electronic configuration of $n{{s}^{2}}n{{p}^{5}}$. Here the outermost p subshell has five electrons in them. If you will check the periodic table this electronic configuration is shown by the halogen family which belongs to group 17 of the periodic table. Therefore the elements can be fluorine $(2{{p}^{5}})$, chlorine $(3{{p}^{5}})$, bromine $(4{{p}^{5}})$, iodine $(5{{p}^{5}})$,etc.

(b) Identify an element that would tend to lose two electrons.
Elements in the periodic table generally lose electrons to attain the stable noble gas configuration. And the elements which have two electrons in their outermost subshell can easily lose the electrons so they can attain the stable noble gas configuration. The electronic configuration of such elements are $n{{s}^{2}}$.And this electronic configuration is only shown by the group 2 elements of the periodic table. Thus the elements will be Be, Mg, Ca, Sr, Ba, Ra.

(c) Identify an element that would tend to gain two electrons.
Elements in the periodic table are likely to gain two electrons when they need only two extra electrons to occupy the stable noble gas configuration.. The electronic configuration shown by such elements should be $n{{s}^{2}}n{{p}^{4}}$. Here two electrons can easily be removed from the outermost p orbital. This type of electronic configuration is shown by the oxygen family thus the elements will be O, S, Se, Te, Po, Uuh.

(d) Identify the group having metal, non-metal, liquid as well as gas at the room temperature.
In the periodic table group 17 (Halogen family) have metals, non-metals, liquid and gas at room temperature. Iodine is a metal whereas chlorine and bromine are the non-metals. Fluorides are present in liquid state while chlorine , bromine and gaseous are present in the form of gases.
So, the correct answer is “Option C”.

Note: Stable configurations are shown by those elements which have their valence shell complete. The no. of electrons in the valence should be 2 or 8. Noble gases have stable configuration because they have 2 or 8 electrons in their valence shell and their valence shell is complete. And they do not share, lose or gain electrons.