what is the element if the quantum numbers for the last electron has the following address n=5 l=3 ml=2 ms=-1/2?
my teacher said the answer is molybdenum but when I count to the 13th electron slot on the 5f row I keep getting nobelium
- 4 weeks ago
n = 5 is the 5th energy level
l = 3 is an f orbital
ml = 2 is one of the 7 f orbital (-3, -2, -1, 0, 1, 2, 3). The one with the 13th electron
ms = -1/2 is the spin on a single electron in this f orbital, i.e. 13th electron
Could this be Mendelevium?
- pisgahchemistLv 74 weeks ago
Quantum numbers .....
n = 5, ℓ = 3, mℓ = 2, ms = -½
This describes an electron in the 5f sublevel
.....7p __ __ __
...........6d __ __ __ __ __
...................5f __ __ __ __ __ _x __
.....6p __ __ __
The element can't be molybdenum since Mo has no f-sublevel electrons. It can't be nobelium since it has a filled 5f sublevel.
In fact the "last" electron description is troublesome because a "down spin" often indicates the second electron in an orbital, and it can't be the "last" electron because one orbital (mℓ=3) must have one electron.
If by "last" you mean the last electron to be written using the Aufbau principle, then the element would be mendelevium (Md).
It's my guess that there is some confusion with the names and symbols of molybdenum (Mo) and mendelevium (Md), and boils down to someone thinking that Md is molybdenum.
- lenpol7Lv 74 weeks ago
Nobelium is on the 7th row. Nobelium would be n = 7
- oeman50Lv 74 weeks ago
The "last" electron for both Nb and Mo is the 5s1, so both have the same quantum numbers. The difference is Nb has 4d4 orbital and Mo has a 4d5. That makes a difference in the overall electron structure but not the last electron.