72 percent is hydrogen. Nuclear fusion converts hydrogen into other elements. The sun is also composed of about 26 percent helium and trace amounts of other elements; oxygen, carbon, neon, nitrogen, magnesium, iron and silicon.
http://www.space.com/17170-what-is-the-sun-made-of.html
By sharing valence electrons between the two atoms
Molarity/ molar is a unit of concentration, symbolized by "M". It is the ratio of the number of moles of solute and the volume of solution.
Molarity = Moles of solute ÷ Liters of solution = moles/liter = M
molarity is define as the number of mole of a solute in 1 liter of solution
The bare rock will erode, once it erodes the rock will no longer be bare cause eroded sediment will cover it.