Atomic mass is usually defined by the total number of protons, neutrons and electrons in a single atom. You can measure it by spectrometry.
Because alcohol expands over small temp changes, hence while a vial of it is used in sprinklers as the stop plug; the room gets hotter, the plug shatters.
Mg2+...because it loses 2 electron which is on its valence shell making it empty and making it have jst 2 shells. The radius calculated from d nucleus to the new valence shell is then smaller than that of Cl^- and k+
Just an example.. This can affect people because it can cause people to bring umbrellas wear rain coats of it were to rain.
Yes. density is a physical property that can be used to identify matter
