Answer: 117?
Step-by-step explanation:
Answer:
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.
Step-by-step explanation:
120
OA = OB
angle OAN = 90 degrees, so OAB and OBA is both 30 degrees.
Answer:
9.
Step-by-step explanation:
The highest power is 3*3 = 9, so it's 9.
