Hydrogen atoms absorb energy so that the electrons are excited to n=4. Calculate the wavelength, in
nm, of the photon emitted when the electron relaxes to n=2.
487nm
456nm
4.56 x 10nm
4.87 x 10-7nm

During your cycling trip, you and your friends often stayed in hostels. the prices of these are listed below. hostel standard room (price per night) with breakfast (price per night) super sleep hostels £22.45 £28.65 normandy nights £18.55 £25 zzzola hostels £24.50 £30.99 belgian beds £11.20 £18.55 night-time rest days ? £33 what is the range in cost for a single night, including both standard room prices and with breakfast prices?

Use the net as an aid to compute the surface area of the triangular prism. a) 550 m2 b) 614 m2 c) 670 m2 d) 790 m2

Jack did 3/5 of all problems on his weekend homework before sunday. on sunday he solved 1/3 of what was left and the last 4 problems. how many problems were assigned for the weekend?