Which two parts of an atom determine the atom's mass?

Describe what happens to the molecules as water goes from ice to liquid to vapor. be sure to explain what happens to the temperature during the phase changes.

How does blood clotting prevent the entry of pathogens through cuts and wounds? answer asap,, this is due tomorrow. will mark as brainliest or whatever you call it : )

Which of the following is an indication that a substance has undergone a chemical change? a. no new product has been formed. b. the color of the substance has not changed. c. the original constitute has not changed. d. the molecular structure has changed.