Someone pls help me. Even if u can’t answer all of them, that’s fine, just pls help

The density of a planet is 0.69 g/cm3 (density of water is 1.0 g/cm3). which of the following planets might this be? a. mercury b. venus c. saturn d. mars

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

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.