. Find the average atomic mass of copper if 7 atoms out of 10 are copper-63 and 3 atoms out of 10 are copper-65.

What is a difference between a mixture of elements and a mixture of compounds

)in the deacon process for the manufacture of chlorine, hcl and o2 react to form cl2 and h2o. sufficient air (21 mole% o2, 79% n2) is fed to provide 35% excess oxygen, and the fractional conversion of hcl is 85%. calculate the mole fractions of the product stream components.

The allotropes of carbon include a variety of structures that include three-dimensional tetrahedral lattices, planes of hexagonal rings, cylindrical tubes of hexagonal rings, and spheres of five- and six-membered rings. similar shapes of network covalent atomic solids are possible with carbon nitride, boron, and pure silicon (e.g., silicene is a graphene-like allotrope of pure silicon). in contrast, silicates exist as either highly ordered or amorphous (more random) three-dimensional lattices. what could explain why there are there no naturally occurring sheets, stacked sheets, cylindrical tubes, or spheres of network covalent atomic solids composed of silicon and oxygen (sio2)? would pure silicate structures make good lubricants or good electrical conductors?