Where does the oxygen come from that is produced as a by-product of photosynthesis?

Every compound can be represented by a chemical formula. a chemical formula is the set of symbols showing the elements that make up a compound and their proportions. water’s chemical formula is h 2 2 o. that means a molecule of water contains two atoms of hydrogen and one atom of oxygen chemically bonded. a molecule is a group of two or more atoms bonded together. molecules can range in size from two to thousands of atoms. a molecule of a compound is the smallest unit of that compound. every molecule of water has all the physical and chemical properties of water. that’s because every molecule of water is made of the same elements in the same proportions: two hydrogen atoms and one oxygen! which of the following is a true statement? a every molecule of the same compound will have different properties. b every molecule of a compound has the same proportion of elements. c molecules can be physically separated into smaller units of a compound. d molecules cannot be represented by chemical formulae.

The tasmanian devil, a marsupial carnivore, is facing extinction due to devil facial tumor disease (dftd) which causes bulging cancerous lumps and lesions to erupt around the face and neck — often causing enough deformation to make seeing or eating difficult. dftd has evolved into a contagious cancer, a trait that is unique among cancers. devil mating behavior involves biting around the head and neck, allowing cells from one individual — especially cells from the crumbly dftd tumors — to be transferred to the wounds or face of a new individual. this marsupial was once found across australia, but sea levels rose, isolating the tasmanian population, while the australian population went extinct. what would be an outcome of genetic isolation that is likely to have impacted the spread of dftd? a) reduced territory puts diseased individuals in greater contact with non-diseased ones. b) inbreeding results in less variation in facial features so the cancer is generally fatal. c) genetic isolation has made it difficult for scientists to develop a vaccine against dftd. d) the lack of genetic variation in the immune system of tasmanian devils minimizes resistance to the disease.

Isotopes of the same element have differ in their