Density= mass/volume aluminum can= 174 •g/ 4 • cm ^3. =2.76•g•cm ^-3
- If the abundance of the first isotope is 68.037%, then the abundance of the second isotope is 100%-68.037%.
Substituting into the atomic mass formula,

Answer:
The number of electrons in the outermost shell of an atom determines its reactivity. Noble gases have low reactivity because they have full electron shells. Halogens are highly reactive because they readily gain an electron to fill their outermost shell.
Explanation: