Question

1. scientists used to believe that chemical reactions fueled the sun. why did this lead them to believe that the sun was very young? what kind of reactions do we now think are responsible for the energy released by the sun? in one to two sentences, explain your reasoning. 3) use the equation (_{6}^{10}c

ightarrow_{5}^{10}b + _{+1}^{0}e) a student claims that the equation models beta - minus decay because the atomic number of the nucleus decreases by one. in one or two sentences, explain the error in the students reasoning.

Explanation:

1. In the past, scientists thought chemical reactions fueled the sun as they were common energy - releasing processes known at the time. Now, we know nuclear fusion reactions power the sun because they can produce vast amounts of energy over long periods consistent with the sun's age and energy output.
2. In beta - minus decay, a neutron in the nucleus is converted into a proton, an electron, and an antineutrino. The atomic number increases by 1, not decreases, because a new proton is formed. The error in the student's reasoning is a misunderstanding of the process of beta - minus decay.

Answer:

1. Initially, chemical reactions were thought to fuel the sun due to their known energy - releasing nature. We now think nuclear fusion powers the sun as it can sustain the sun's energy output over its long lifetime.
2. The student is wrong because in beta - minus decay, the atomic number increases by 1 as a neutron turns into a proton, not decreases.