Question

20 multiple choice 4 points define a period. diagonal on the periodic table from left to right (same as energy levels) same properties ( same as the group #) (columns) the elements in a family all react differently

Explanation:

In the periodic table, periods are the horizontal rows. Elements in a period have the same number of electron - energy levels and are arranged from left to right.

Answer:

From Left to Right (Same as Energy Levels)