What nuclide is formed when 90Sr undergoes β
− decay?
1. 90Rb
2. 86Kr
3. 89Sr
4. 94Zr
5. 90Y

The graph has an initial value of 60, and each successive term is determined by multiplying by One-third.

Step-by-step explanation:

Which is the best description of the graph of the function f(x) = 60(One-third)x?

A. The graph has an initial value of 20, and each successive term is determined by subtracting One-third.

B. The graph has an initial value of 20, and each successive term is determined by multiplying by One-third.

C. The graph has an initial value of 60, and each successive term is determined by subtracting One-third.

D. The graph has an initial value of 60, and each successive term is determined by multiplying by One-third.

Given:

f(x) = 60 (1/3)^x         see graph attached.

Examining the graph, we notice that

1. The graph has an initial value of 60, at point (0,60)

2. The graph decreases as x increases.  Each successive term is determined by multiplying by 1/3, namely in the sequence

{(0,60), (1,20), (2, 20/3), (3, 20/9), ...}

This means the choice is D (or the fourth one).