A phosphorus ion with a charge of -2 has _ protons neutrons,and electrons
The Correct Answer and Explanation is :
A phosphorus ion with a charge of -2 (denoted as ( \text{P}^{2-} )) has the following characteristics:
- Protons: 15
- Neutrons: 16 (assuming the most common isotope)
- Electrons: 17
Explanation:
- Protons:
The number of protons in an atom is determined by its atomic number. Phosphorus (P) has an atomic number of 15, meaning it contains 15 protons in its nucleus, regardless of whether it is in its neutral or ionized form. - Neutrons:
Neutrons, along with protons, make up the mass of an atom. The number of neutrons in an atom is typically determined by subtracting the atomic number (the number of protons) from the atom’s mass number (the total number of protons and neutrons). The most common isotope of phosphorus has a mass number of 31. Therefore, the number of neutrons in this isotope is: [
\text{Neutrons} = \text{Mass number} – \text{Protons} = 31 – 15 = 16
]
So, this phosphorus atom has 16 neutrons. - Electrons:
In a neutral atom, the number of electrons equals the number of protons. Since phosphorus has 15 protons in its neutral state, it would also have 15 electrons. However, in the case of a ( \text{P}^{2-} ) ion, it has gained two extra electrons to acquire a negative charge. Therefore, the number of electrons in a ( \text{P}^{2-} ) ion is: [
15 \, \text{(protons)} + 2 = 17 \, \text{electrons}
]
In summary, a ( \text{P}^{2-} ) ion has:
- 15 protons,
- 16 neutrons (assuming the most common isotope),
- 17 electrons.