2) Which of the following is a true statement? A: All the atoms of an element must be identical. B: Compounds may be separated by physical means. C: Mixtures may not be separated. D: Homogeneous is one type of compound. 3) Which of the following is a true statement? A: Organic carbon is found in all non-living things B: A compound has different properties from each C: Water is made from the elements of carbon and D: Hydrogen compounds are the most common in the world​