What do the groups (columns) and periods (rows) tell you about the elements on the periodic table?

Groups: The vertical column of the periodic table that signifies the number of valence electrons in an element.

Period: The horizontal rows in the periodic table that signify the number of electron shells in an element.

Explanation:

Groups: The vertical column of the periodic table that signifies the number of valence electrons in an element. Periods: The horizontal rows in the periodic table that signify the number of electron shells in an element.

Explanation:

The table has seven rows and 18 columns. Each row represents one period; the period number of an element indicates how many of its energy levels house electrons.The columns of the table represent groups, or families, of elements.

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)