After using the yum install command, you will be prompted for the computer's root password. Type in the root password and press 'Enter'. You will not see the password as you type. The terminal will start giving information about the application, and end with Is this ok [y/N]:.
While some of the compounds in the dirt and rock are the same in most coal, the carbon is combined here and there with hydrogen, oxygen, sulphur, nitrogen, phosporus and just about every other common element in small quantities. Imagine an extremely large net where the knots are carbon atoms.
Coal is a chemically complex fuel. Whenever it is burned, gases are given off and particles of ash, called fly ash, are released. The sulfur in coal combines with oxygen to form sulfur dioxide, which can be a major source of air pollution if emitted in large enough quantities.