ALL of the quantities are unknown, because you haven't bothered to tell us anything that's known.
A and B are the correct answer for this
The answer is:
B)They are in the same group because they have similar chemical properties, but they are in different periods because they have very different atomic numbers.
The 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.
A period is a horizontal row of elements on the periodic table. For example, the elements sodium ( Na ) and magnesium ( Mg ) are both in period 3. The elements astatine ( At ) and radon ( Rn ) are both in period 6.
I believe it’s OH have a good day
Explanation:
Speed: distance/time
Average speed: total distance/total time
Total distance: 400
Total time: 60
Average spead: 400/60= 6.67m/s
