I Need help ASAP An unknown element is a mixture of isotopes ¹²⁰X and ¹²²X. The average atomic mass of X is 120.59 amu. What is the percent abundance of ¹²²X?

An animal cell loses the ability to convert energy stored in food to energy that the cell can use. which of the cell's organelles has stopped working? a.the mitochondria b.the nucleus c.the vacuoles d.the endoplasmic reticulum

Light waves can move through , but they travel fastest when they move through a(n) .

Which statement best summarizes the importance of ernest rutherford’s gold foil experiment? it proved that all of john dalton’s postulates were true. it verified j. j. thomson’s work on the atomic structure. it showed that an electron circles a nucleus in a fixed-energy orbit. it showed that a nucleus occupies a small part of the whole atom.