1. physics/chemistry

Being a chemistry major, i thought i understood what what going on in this problem! i was very discouraged to learn that i was wrong! If you can help...that would be great!

Grains of fine California beach sand are approximately spheres with an average radius of 50 μm and are made of silicon dioxide, which has a density of 2.7 × 103 kg/m3. What mass of sand grains would have a total surface area (the total area of all the individual spheres) equal to the surface area of a cube 1.2 m on an edge?

2. Originally Posted by massid
Being a chemistry major, i thought i understood what what going on in this problem! i was very discouraged to learn that i was wrong! If you can help...that would be great!

Grains of fine California beach sand are approximately spheres with an average radius of 50 μm and are made of silicon dioxide, which has a density of 2.7 × 103 kg/m3. What mass of sand grains would have a total surface area (the total area of all the individual spheres) equal to the surface area of a cube 1.2 m on an edge?