Question

Name
(i) Two elements that have a single electron in their outermost shells.
(ii) Two elements that have two electrons in their outermost shells.
(iii) Two elements with filled outermost shell.
(iv) Two elements that belong to halogen family.
(v) An element which is tetravalent and forms the basis of organic chemistry.

Answer 1

(i) Lithium (Li), sodium (Na), and potassium (K) have a single electron in their outermost shells. 
(ii) Magnesium (Mg) and calcium (Ca) have two electrons in their outermost shells. 
(iii) Neon (Ne), argon (Ar), and xenon (Xe) have filled outermost shells.
(iv) The halogen elements are fluorine (F), chlorine(Cl), bromine (Br)
(v) Carbon