Answer:
A) It tends to increase from top to bottom of a group
PLEASE POST YOUR QUESTIONS IN ENGLISH, ANYONE CAN REPORT YOU FOR DOING THIS BE CAREFULL
The answer is hydrogen. the first element in the periodic table.
Explanation:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.
Noun!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
