Answer : The correct option is, '24'
Explanation :
Element = Chromium
Atomic number = 24
Mass number = 52
The electronic configuration of chromium atom is,

As per electronic configuration, the number of electrons are = 24
or,
Atomic number = Number of electrons = Number of protons
Mass number = Number of protons + Number of neutrons
As we know that the atomic number is equal to the number of electrons. So, the number of electrons in an uncharged atom of chromium are '24'.