Answer:
1. Proton = 4
2. Neutron = 5
3. Electron = 2
Step-by-step explanation:
9 4Be^2+
From the above, we obtained the following:
Atomic number = 4
Mass number = 9
Charge = +2
1. Determination of the proton.
Atomic number is simply defined as the proton number. This implies that:
Atomic number = proton number
Atomic number = 4
Therefore,
4 = proton number
Proton = 4
2. Determination of the Neutron.
Mass number = Proton + Neutron
Mass number = 9
Proton = 4
Neutron =?
Mass number = Proton + Neutron
9 = 4 + Neutron
Collect like terms
Neutron = 9 – 4
Neutron = 5
3. Determination of the electron.
From the question given
9 4Be^2+
The atom has a charge of +2. This implies that the atom has lose 2 electrons. Thus we can obtain the electron as follow:
Proton = 4
Charge = +2
Electron =?
Electron = Proton – charge
Electron = 4 – 2
Electron = 2