Explain why Gold is preferable to iron in making of sewelleries​

Idid the calculation and i get 875,000,000 which can be written as 8.75 x 10^6?

It will fall off and tip over. 

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).