Explain why we have to BALANCE CHEMICAL EQUATIONS

Fugu, also known as puffer fish, is a sushi delicacy that can also be lethal. puffer fish contain a powerful toxin that can kill an adult a few hours after ingestion. sushi chefs who prepare fugu must be specially trained because any contamination of the toxin-free areas of the fish can be deadly. recently this toxin has been put to good use, as scientists have discovered that a purified form of it can treat severe pain in cancer patients. this recent scientific discovery would fall under which area of chemistry? applied biochemistry pure organic chemistry pure physical chemistry applied inorganic chemistry

56.16 gregor mendel was the first scientist to use statistics to analyze scientific data. before mendel's experiments, scientists believed that organisms acquired traits from their environment and passed them on to their offspring. after mendel's discoveries were accepted, scientists realized that traits passed to offspring were the result of genes being passed from parents to offspring. this is an example of pls

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.