How many orbitals sit in the p and d sub-shells?
- One and three
- Three and five
- Five and seven
How many electrons can one orbital hold?
The 4s sub-shell fills before 3d.
Circle one: True False
What is the configuration of the iron(II) ion?
- 1s2 2s2 2p6 3s2 3p6 4s2 3d4
- 1s2 2s2 2p6 3s2 3p6 3d6 with empty 4s
- 1s2 2s2 2p6 3s2 3p6 4s1 3d5
What is the full configuration of iron, with 26 electrons?
- 1s2 2s2 2p6 3s2 3p6 4s2 3d6
- 1s2 2s2 2p6 3s2 3p6 3d8
- 1s2 2s2 2p6 3s2 3p6 4s2 4p6
Why is copper 4s1 3d10 instead of 4s2 3d9?
- Copper holds 30 electrons
- 4s can hold three electrons
- A full d set is extra stable
An element sits in the d block of period 4. Which sub-shell is filling across its row?
A student draws oxygen 2p as two pairs. What is wrong?
- Boxes fill singly first, so oxygen 2p is one pair plus two singles
- Oxygen has no p electrons
- Pairs are never allowed
Addresses for every electron W1-mt_sRMo1f5PfJ-s1
- Three and five · Three boxes for p, five for d.
- Two · Every orbital fits at most two.
- True · At that point 4s sits lower in energy.
- 1s2 2s2 2p6 3s2 3p6 3d6 with empty 4s · Both 4s electrons leave first, leaving 3d6.
- 1s2 2s2 2p6 3s2 3p6 4s2 3d6 · Fill in order to 26 and 4s lands before 3d.
- A full d set is extra stable · One shifted electron completes the d set.
- 3d · The middle ten columns fill the 3d seats.
- Boxes fill singly first, so oxygen 2p is one pair plus two singles · Each box takes one arrow before any pairing starts.