Answer:
C
Explanation:
Vector A points up
Vector B points right
The combination must be both up and right which is C
(4.2*10^5)*(4*10^-9) = 1.68* 10^-3
With 30degree because incident angle = reflected angle
According to the periodic table, all the elements, except hydrogen, are considered alkaline metals. ie. Li, Na, K, Rb, Cs, Fr.
