Question

which is not true of the $\ce{sc^3+}$ ion?

a) it was formed by the loss of 4s and 3d electrons.

b) it is considered to be a different element than a neutral sc atom.

c) it has the same electron configuration as ar.

d) it is a scandium ion with three positive charges.

Explanation:

Step 1: Analyze Option A

Scandium (Sc) has an electron configuration of $[Ar] 4s^2 3d^1$. To form $Sc^{3+}$, it loses 2 electrons from the 4s orbital and 1 electron from the 3d orbital. So, it is formed by the loss of 4s and 3d electrons. Option A is true.

Step 2: Analyze Option B

The identity of an element is determined by the number of protons (atomic number). A neutral Sc atom and $Sc^{3+}$ ion have the same number of protons (atomic number of Sc is 21). So, they are the same element. Option B is not true.

Step 3: Analyze Option C

The electron configuration of $Sc^{3+}$: After losing 3 electrons (2 from 4s and 1 from 3d), its electron configuration becomes $[Ar]$, which is the same as argon (Ar). Option C is true.

Step 4: Analyze Option D

$Sc^{3+}$ is a scandium ion with a charge of +3, meaning it has three positive charges. Option D is true.

Answer:

B. It is considered to be a different element than a neutral Sc atom.