The ion of an element has positive charges. Mass number of the atom is and the number of neutrons is . What is the number of electrons in the ion?
Given:
Number of positive charges on ion
Mass number
Number of neutrons
Formula used:
Mass numberAtomic numberNumber of neutrons
Calculate the atomic number of the element:
Mass numberAtomic numberNumber of neutrons
Thus,
Atomic numberMass numberNumber of neutrons
Thus,
Atomic number
Atomic number
Thus, the atomic number of the element is .
Calculate the number of electrons in the neutral atom:
In a neutral atom, the number of electrons is equal to the atomic number.
Thus,
Number of electrons in the atom
Calculate the number of electrons in the ion having three positive charges:
An ion having positive charges is formed. This shows that the atom has lost electrons.
Thus,
Number of electrons in ion
Thus, the number of electrons in the ion is .
Thus, Option (B) is the correct option.