One proton, three numbers, every shape

Science · Chemistry · ages 18-19

Name ______________________ Date ____________

The label set n = 2, l = 0 is given. Which orbital is it?
- 2p
- 2d
- 2s
Which quantum number sets the energy and size in hydrogen?
- l, the shape number
- n, the principal number
- ml, the orientation number
What does the tallest peak of a radial plot tell you?
- The most likely distance of the electron
- The speed of the electron at that point
- The total charge carried at that point
A plot shows one spherical shell of zero probability plus one flat plane. Which orbital fits?
- 3s
- 3p
- 2p
How many total nodes does any n = 4 orbital have?
Answer: ______________
Why do 2s and 2p share one energy in hydrogen?
- They share the same shape
- The nucleus treats every orbital alike
- Energy depends only on n in hydrogen
Which proposed label set is impossible?
- n = 3, l = 1
- n = 2, l = 2
- n = 3, l = 0
A student labels an orbital 3d with 2 radial nodes and 1 angular node. What is the error?
- The total is 3, but n = 3 allows only 2
- d orbitals can never have radial nodes
- The student counted the nucleus twice

Answer key

For grown-ups. Fold this page away before handing over the rest.

2s · The letter s is the nickname for l = 0.
n, the principal number · Size and energy both answer to n in hydrogen.
The most likely distance of the electron · Peaks of the radial plot are the most probable distances.
3p · One shell plus one plane adds to 2, which matches n = 3.
3 · Every hydrogen orbital carries n minus 1 total nodes.
Energy depends only on n in hydrogen · With one electron there is nothing for shape to act on.
n = 2, l = 2 · The shape number must stay below n.
The total is 3, but n = 3 allows only 2 · Node totals catch bad labels fast.