Answer:


Explanation:
See attachment for complete work.
Answer:
A
Explanation:
So a pulse is a part of a mechanical wave, and mechanical waves are energy transfer trough some medium, in this case a stretched spring. So the correct answer is (A) energy only. The pulse cant be transferred into mass.
Answer:
Explanation:
A positive v time graph is a velocity graph. If the position/time is negative, then the slope of the line is negative. If the line is indicative of the velocity, which it is, that means that the velocity is negative (decreasing). The first choice is the one you want.
The elements found in the Group 1, or the Alkali Metal Group, have electronic configurations that end in

.This means that they have 1 electron readily available to release in order to achieve a stable state.
When these atoms release the valence electron, they will achieve a stable state. For example, Lithium's stable state will be

and Sodium will be

.
The oxidation state will then be +1.
The answer is C.