If an atom has 15 protons and a mass of 31 how many neutrons will it have

Which statement about the stamps is correct?

2. what two items do autotrophs take from the environment to produce their food? 3. what are the two items that are released during transpiration from leaves? 4. what are the two membranes of the system? a.what are the two stages of photosynthesis? what are the two parts of photosynthesis?

Choose the correct statement about licensed veterinarians in the united states. a. they must be certified by the avma. b. they can treat all nonhuman animals. c. they can can treat only animals specified on the license. d. they must choose a specialty.