So we expect that the description of the velocities of molecules in a gas will in fact be the most probable distribution, since we are dealing with particle numbers in the range of Avogadro's number. But this most probable distribution (the Maxwell-Boltzmann distribution) is subject to constraints, namely that the number of particles is constant and that the total energy is constant (conservation of energy).
The oldest rocks are metamorphic gneisses which are to be found on Inishtrahull, several miles off Malin Head in Co. Donegal, and elsewhere in the north-west. They originally formed as igneous rocks 1750-1780 million years ago.
Rocks resulting from cooled-off lava include obsidian, lava rock, basalt or pumice. These are known as extrusive igneous rocks because they are formed outside of the crust. There are about 700 different types of igneous rock. More examples of igneous rocks include tuff, diorite and andesite.Here are some uses of igneous rocks: Granite is used for building and construction because of its strong properties. It is also used for head stones and kitchen counter tops.here are about 700 different types of igneous rock. More examples of igneous rocks include tuff, diorite and andesite. Here are some uses of igneous rocks: Granite is used for building and construction because of its strong properties. It is also used for head stones and kitchen counter tops.