The active volcano Mauna Loa, in Hawaii, and the now-extinct volcano El Yunque, Puerto Rico, have certain basaltic lava rocks containing the element selenium. Typically, a 25.0 g rock contains 0.005 g of selenium. What is the concentration of selenium in these lava rocks, in ppm?

Which type of bonding involves the complete transfer of a valence electron from a less electrogrative atom to a more electronegative one

Melting and boiling are endothermic processes. this means that these processes absorb energy from their surroundings in order to occur. use this information and the data you collected in the phase change gizmo to describe what happens to the temperature of water when you boil it, then explain why this result occurs.

The formation of a solid, also known as a is an indication of a chemical change. precipitate particulate particle powder