Question

if two elements are listed in the same vertical column, what does this mean?
they create a gas when they react with one another.
they have many properties in common.
they have the same atomic mass.
they react easily with one another.

Explanation:

Elements in the same vertical column (group) of the periodic table have the same number of valence electrons, which leads to them having many similar chemical and physical properties.

Answer:

They have many properties in common.