Question

In a star's core the average mass number for ions which are not hydrogen or helium is 10.The mass fraction of hydrogen is 0.60,of helium is .38 and all other elements is. 02.Calculate the average ion mass in units of mh.

Answer 1

$$M=0.6m_h+0.38m_{He}+0.02m\\M=0.6m_h+0.38(4)m_h+0.02(10)m_h\\M=2.32m_h$$