Question

1. which mathematical model best illustrates the changing proportions of hydrogen and helium over the suns lifespan? graph b, because both hydrogen and helium decrease as mass is converted to energy. graph a, because helium increases as hydrogen decreases. graph a, because hydrogen increases as helium decreases. graph b, because hydrogen decreases as helium decreases. neither of these graphs accurately represents the relationship between hydrogen and helium.

Explanation:

Step1: Recall nuclear - fusion in the Sun

In the Sun, hydrogen fuses into helium through nuclear - fusion. As time passes, the amount of hydrogen decreases and the amount of helium increases.

Step2: Analyze Graph A and Graph B

In Graph A, the abundance of hydrogen (H) is decreasing and the abundance of helium (He) is increasing over time, which is consistent with the nuclear - fusion process in the Sun. In Graph B, both hydrogen and helium abundances are decreasing, which is not correct according to the nuclear - fusion process.

Answer:

Graph A, because helium increases as hydrogen decreases.