The density of aluminum is 2.7 g/cm3 ; that of silicon is 2.3 g/cm3 . Explain why Si has the lower density even though it has heavier atoms.

What is the mass of 8 moles of sodium atoms

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.

Harry lives in a city, and he has a lung condition known as asthma. on certain days, harry has to stay inside because pollutants in the air make it difficult for him to breathe. which of these pollution sources are nonpoint sources that might bother harry if he goes outside? choose the two that apply.