What are columns on the periodic table called? What is the significance of the columns on the periodic table?

The vertical columns of the periodic table are called groups, or families. The significance is elements with similar properties are placed in the same vertical columns. The horizontal rows of the periodic table are called periods. The significance is that properties vary from left to right along the rows.

Explanation:

We just did this in science

the answer is na (sodium)

i think that the answer is c