The total number of protons, neutrons, and electrons in a neutral bromine (Br) atom with a mass number of 80 is 115.
Understanding the composition of an atom is fundamental to chemistry. Every atom is made up of subatomic particles: protons, neutrons, and electrons. The specific number of each particle defines an element and its isotopic form. For a neutral bromine atom with a mass number of 80, we can determine the count for each of these particles.
Breakdown of Subatomic Particles
To arrive at the total count, we identify the number of each particle individually.
Protons
The number of protons in an atom defines its atomic number and, consequently, the element itself. For bromine (Br), its atomic number is 35. This means that every bromine atom, regardless of its isotope, contains exactly 35 protons in its nucleus.
Neutrons
The mass number of an atom represents the total count of protons and neutrons in its nucleus. Given that this particular bromine atom has a mass number of 80, and we know it has 35 protons, the number of neutrons can be calculated by subtracting the number of protons from the mass number:
- Mass Number = Protons + Neutrons
- 80 = 35 + Neutrons
- Neutrons = 80 - 35 = 45
Therefore, a bromine atom with a mass number of 80 contains 45 neutrons.
Electrons
In a neutral atom, the number of negatively charged electrons orbiting the nucleus is equal to the number of positively charged protons within the nucleus. This balance ensures that the atom has no net electrical charge. Since a neutral bromine atom has 35 protons, it must also have 35 electrons.
For more information on atomic structure and subatomic particles, you can refer to resources like Chemistry LibreTexts on Atomic Structure.
Total Count Summary
Here is a summary of the subatomic particles in a neutral bromine (Br) atom with a mass number of 80:
| Particle | Number |
|---|---|
| Protons | 35 |
| Neutrons | 45 |
| Electrons | 35 |
| Total | 115 |
By summing the number of protons, neutrons, and electrons, we find the total number of these subatomic particles is 35 + 45 + 35, which equals 115.
