Final answer:
Elements with the ns1 electron configuration belong to the highly reactive alkali metals family, which includes lithium, sodium, potassium, rubidium, cesium, and francium.
Step-by-step explanation:
Elements that end in the electron configuration ns1 belong to the family of alkali metals. These elements, which include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr), are positioned in group 1 of the periodic table. They have one valence electron in an s orbital, which accounts for their high reactivity. Alkali metals are known for reacting vigorously with water, and they tend to form positively charged ions by losing this loosely bound outer electron.
The alkali metals are not to be confused with the alkaline earth metals of group 2, which contain two valence electrons and are also reactive, but to a lesser extent than the alkali metals. Unlike the alkali metals, alkaline earth metals have a higher first ionization energy and when reacting chemically, they lose both valence electrons to achieve an oxidation state of 2+.