if two atoms are held together by a triple covalent bond, how many pairs of electrons are the two atoms sharing in their outermost shells

The metal is named first

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).