Question

which set of elements should have similar chemical properties?
potassium (k), calcium (ca), and scandium (sc)
lithium (li), sodium (na), and potassium (k)
boron (b), silicon (si), and aluminum (al)
hydrogen (h) and helium (he)

Explanation:

Elements in the same group (vertical column) of the periodic table have similar chemical properties. Lithium (Li), Sodium (Na), and Potassium (K) are all in Group 1 (alkali metals). Potassium (K) is Group 1, Calcium (Ca) is Group 2, Scandium (Sc) is Group 3 - different groups. Boron (B) is Group 13, Silicon (Si) is Group 14, Aluminum (Al) is Group 13 - not same group. Hydrogen (H) is Group 1 (but a non - metal with some unique properties), Helium (He) is Group 18 (noble gas) - different groups.

Answer:

Lithium (Li), Sodium (Na), and Potassium (K)