4.) How do you determine the
mass number of an atom?

the mass number or mass number is the sum of the number of protons and the number of neutrons in the nucleus of an atom. It is symbolized by the letter A (the use of this letter comes from the German Atomgewicht, which means atomic weight, although they are different concepts that should not be confused).

answer; ///as energy flows through an ecosystem,energy (decreases) at each

the correct answer is option b

behavioral response need communication and thus co-ordination at several levels such as interaction among cells, organ system and the entire organism.

behavioral response produces both internal and environmental stimulus.