What is the mass number of an atom thy contains 42 protons, 42 elections, and 53 neutrons

Which of the following typically characterizes a tropical rainforests

Which of the following words best matches this definition: the process in which the best adapted organisms survive and pass on their traits, while those that are not well adapted do not survive to pass on their traits. question 3 options: acquired selection natural selection artificial selection organic selection

Which of the following happened during the precambrian era? the first prokaryotic cells the first eukaryotic cells development of photosynthesis all of the above