Which ion has twenty-eight electrons?
We’re being asked which among the given ions has twenty-eight (28) electrons.
An element can be represented as:
You can determine the identity of the element using its atomic number:
Atomic number (Z):
• represents the identity of the element
• reveals the number of protons
• in a neutral element:
# of protons = # of electrons
Mass number (A)
• reveals the number of protons and neutrons
mass number = # of protons + # of neutrons
Given: # of electrons = 28 e-