What is the spectral class of a main sequence star with a luminosity 100,000 (105) times that of the Sun?

Choose all the answers that apply. fluorine (f) has an atomic number of 9 and an atomic weight of 18.99. fluorine has a. 9 protons b. 10 neutrons c. 18 electrons d. an atomic mass of 19 e. at least one isotope

Why is it that 85.48 rounded to two significant figures is 85 and not 86?

What three relationships are true at equilibrium