81 protons and 78 electrons Express your answer as an ion.
The correct answer and explanation is :
The given atom has 81 protons and 78 electrons. Since the number of protons determines the element, we can identify the element as Thallium (Tl) because Thallium has an atomic number of 81.
To determine the charge of the ion, we use the formula: Charge=Number of protons−Number of electrons\text{Charge} = \text{Number of protons} – \text{Number of electrons} Charge=81−78=+3\text{Charge} = 81 – 78 = +3
Thus, the correct way to express this ion is: Tl3+\mathbf{Tl^{3+}}
Explanation:
- Understanding Protons, Electrons, and Charge:
- Protons are positively charged subatomic particles found in the nucleus.
- Electrons are negatively charged subatomic particles that orbit the nucleus.
- An atom is neutral when it has an equal number of protons and electrons.
- When an atom loses electrons, it becomes a positively charged ion (cation).
- When an atom gains electrons, it becomes a negatively charged ion (anion).
- Determining the Charge:
- A neutral Thallium (Tl) atom has 81 protons and 81 electrons.
- The given ion has 78 electrons, meaning it has lost 3 electrons.
- Losing electrons results in a positive charge.
- Since it lost 3 electrons, its charge is +3.
- Why Tl³⁺ is a Common Ion:
- Thallium is a post-transition metal and can form multiple oxidation states.
- The most common oxidation states of Thallium are +1 and +3.
- In this case, it has lost three electrons, forming the Tl³⁺ ion.
Final Answer:
Tl3+\mathbf{Tl^{3+}}
This notation correctly represents the Thallium ion with 81 protons and 78 electrons.