Analyze the picture above. What concept from class does this picture represent? Give evidence to support claim. pls help 50 points <<3

Which physical feature minimizes population density in northern africa?

Clouds thar look like whisps of hair are

Ascientist performs an experiment where she measures the mass of a piece of metal, pours acid onto the metal, washes the metal, and then re-measures the mass of the metal. the scientist repeats the experiment several times, each time increasing the amount of acid used. the dependent variable in the experiment is the: initial mass of the metal final mass of the metal amount of acid used washing the metal