Question

question 8
5 pts
which of the following elements belong to the same group on the periodic table?
sodium and hydrogen
boron and calcium
hydrogen and helium
potassium and chlorine

Explanation:

Elements in the same group of the periodic table have the same number of valence electrons. Sodium (Na) and hydrogen (H) are both in Group 1. Sodium is an alkali - metal and hydrogen is a non - metal but they have 1 valence electron each. Boron is in Group 13 and calcium in Group 2. Hydrogen is in Group 1 and helium in Group 18. Potassium is in Group 1 and chlorine in Group 17.

Answer:

Sodium and hydrogen