Question

drag and drop the words or phrases that accurately complete the summary. the smallest building block of matter, called atoms, are organized into elements on the periodic table. elements are grouped into vertical columns based on their number of electrons. these groups of elements, with the same number of outermost electrons, have similar. the periodic table is organized by of elements, whose group members have similar characteristics due to the same number of valence electrons. the five main families on the periodic table are

Explanation:

Elements in the periodic table are grouped vertically by the number of valence electrons. Elements with the same number of outermost (valence) electrons have similar chemical properties. The table is organized into families where members share similar characteristics due to valence - electron similarity.

Answer:

First blank: valence
Second blank: properties
Third blank: families