Wind becuase you can feel it whhich is physical
Answer: how much mass is in a certain amount of space
Explanation: density is g/mL; therefore it’s the mass (g) in a certain amount of space (mL)
The number of protons uniquely identifies the element. This is not on the periodic table. Isotopic notationincludes the atomic number and the mass number. 8 17 This isotope of oxygen has 8 protons (atomic number), 8 electrons and 9 neutrons
