What is the mass of 5.00 x 1024 molecules of NH3?

Which type of orbits are found in the principal energy level n = 2 a - s b - s, f c - s, d d - s, p e - s, p, d

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

Earth's axis of rotation is tilted at an angle of 23.5 degrees. what is one change you would see on earth if its axis was not tilted?