Fill-in-the-blank
word box (one term per response - no repeating, but you will not use every term):
*metabolism
*covalent
electrons
hydrogen ions
*protons
*ionic
*controlled experiment
18. an experiment in which only one variable is changed is a(an)
_experiment
19. the combination of chemical reactions through which an organism builds up or breaks down
materials as it carries out its life processes is called
20. neutrons and
are found in the nucleus of an atom.
21. a chemical bond formed by the transfer of electrons is a(an)
bond
22. the ph scale is a measurement system that indicates the concentration of
in a solution