here in this to counted the energy of an electron found in the second shell of the hydrogen atom. Alright, since we're looking for the energy of an electron within a given shell, we're looking for its potential energy. It's energy of position. So Delta e equals negative are times Z squared over and squared. Our is our riper constant. So that's negative. 2.178 times 10 to the negative 18 jewels. Z equals the atomic number of the element. Since its hydrogen, its atomic number is one so that be one squared, divided by and squared. Remember? And here is the energy level or shell number. They tell us that the second shell so and equals two. So I'd be two squared. So here, that's negative. 2.178 times 10 to the negative. 18 Jules one squared is just 12 squared is four. So that comes out to negative 5. times 10 to the negative 19 jewels. Since it doesn't give us a number of sig figs in the beginning of the question at all, we could determine our own number of Sig figs here. I'm just going with four significant figures in terms of the potential energy for that particular electron