Alexa is writing a paper comparing elements and compounds found in living and nonliving things. Which of the following could Alexa use to correctly describe the relationship between elements and compounds? *
A. Two compounds are required to make one element in natural systems.
B. Compounds combine in different ways to create many variations of elements.
C. There is a finite number of elements that can be used to create a multitude of compounds.
D. Every elements can be broken down into an infinite number of compounds.

Astudent throws a water balloon with speed v0 from a height h = 1.76 m at an angle θ = 21° above the horizontal toward a target on the ground. the target is located a horizontal distance d = 9.5 m from the student’s feet. assume that the balloon moves without air resistance. use a cartesian coordinate system with the origin at the balloon's initial position. (a) what is the position vector, rtarge t, that originates from the balloon's original position and terminates at the target? put this in terms of h and d, and represent it as a vector using i and j. (b) in terms of the variables in the problem, determine the time, t, after the launch it takes the balloon to reach the target. your answer should not include h. (c) create an expression for the balloon's vertical position as a function of time, y(t), in terms of t, vo, g, and θ. (d) determine the magnitude of the balloon's initial velocity, v0, in meters per second, by eliminating t from the previous two expressions.