Answer:
Scandium (Sc)
Explanation:
Cr³⁺ is a chromium atom that has lost 3 electrons. A chemical specie becomes positively charged when the number of electrons is lower than the number of protons.
In this regard, the number of protons is more.
Chromium originally has 24 electrons, on losing 3 electrons it will now have 21 electrons.
The atom with 21 electrons in its neutral state is scandium
