Random question?

A student performs an experiment and the results are shown below: Before- Iron filings are brown, small, and magnetic: Copper sulfate crystals are blue, brittle, and not magnetic. After- The copper formed was reddish, solid, and not magnetic: Iron sulfide solution was colorless and not magnetic. Which statement supports that a chemical reaction took place?

Random question?

Why do dogs have most of the characteristics of their parents?

Random question?

The water contained in a geyser system gains energy from the underground material surrounding it. The water molecules gain kinetic energy and this results in an increase in the pressure of the water. Eventually the geyser erupts and expels water into the air above ground. Which of the following types of energy is the source for the initial energy gain of the water?

Random question?


Census data show that the human population doubled from 2.65 billion in 1953 to 5.3 billion in 1990. If it continues to double at this rate, the human population could reach 10 billion by the year 2020. Which best explains how this rate of human growth can harm the environment on which humans depend?