Chem. Help??

Question

1. What is the wavelength of a 19F+ ion which is moving with a speed of 4.255x10^5 m/s?

2. In what row or period of the periodic table do we encounter a d-electron? 4, 3, 5, 6, 2
I think the correct one is period 3?

Answer 1

1) The de Broglie equation: momentum x wavelength = Planck's Constant

and, of course, mass x velocity = momentum

Watch your units; you need mass in kg to stay consistently SI.

2) is a bit of a trick Q. The first set of d orbitals are 3d, but they only come into play after the 4s.