Respuesta :

Answer:MARK BRAINLY PLSS

Explanation:

The chemical elements are arranged in order of increasing atomic number. The horizontal rows are called periods and the vertical columns are called groups. Elements in the same group have similar chemical properties. This is because they have the same number of outer electrons and the same valency.

jasonAB

Answer:

Fixed sizes

Explanation:

Atoms in groups are similar because they are all of the same sizes and shapes