An electron transitioned from the 8th shell to the 1st shell in a helium (He) atom. Rydberg constant for hydrogen (RH) is 2.178 x 10-18 J. The change of energy for the electron is: (a) -1.63 x 10-18 J​
(b) -8.58 x 10-18 J
(c) 2.57 x 10-18 J​
(d) -5.87 x 10-18 J

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

Mitosis is a type of cell division that produces cells that are identical to the parent cell. meiosis is a different type of cell division that produces cells that carry have a genetic material of the parent cell. based on the information provided how do the purpose of mitosis and meiosis differ

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.