Which of the following does not have eight valence electrons? Rb O Xe Sr+ Ti4+ Submit Request Answer
The Correct Answer and Explanation is:
Correct Answer: Ti⁴⁺
Explanation:
Valence electrons are the electrons found in the outermost energy level of an atom. Most atoms are most stable when they have eight valence electrons. This is called the octet rule. However, ions form by either gaining or losing electrons to achieve this stable configuration. Let’s evaluate each species:
1. Rb (Rubidium)
Rubidium is in Group 1 of the periodic table, meaning it has 1 valence electron.
So, Rb does not have eight valence electrons in its neutral state. However, this question asks for which species does not have eight valence electrons, and more importantly, others are ions and noble gases, implying a comparison with stable electron configurations. Still, we will consider all of them.
2. O (Oxygen)
Oxygen has 6 valence electrons in its neutral state. To achieve an octet, it tends to gain 2 electrons, becoming O²⁻. But the question does not mention O²⁻, just O.
So Oxygen (O) in its neutral form does not have eight valence electrons.
3. Xe (Xenon)
Xenon is a noble gas in Group 18, which naturally has eight valence electrons.
So, Xe has eight valence electrons.
4. Sr⁺ (Strontium ion with a +1 charge)
Strontium is in Group 2 and has 2 valence electrons in its neutral form. When it loses 1 electron (Sr⁺), it has 1 valence electron left. Therefore, Sr⁺ does not have eight valence electrons.
5. Ti⁴⁺ (Titanium ion with a +4 charge)
Titanium normally has 4 valence electrons (in Group 4). Ti⁴⁺ means it has lost all four of its outer electrons, leaving it with an electron configuration like that of a noble gas (specifically Argon). However, the actual valence shell is now empty, and it does not have any valence electrons.
Therefore, Ti⁴⁺ definitely does not have eight valence electrons.
Final Conclusion:
While several of these species do not have eight valence electrons, Ti⁴⁺ stands out because it has zero valence electrons, having lost all its outer-shell electrons. This makes Ti⁴⁺ the best answer among the choices given.
Answer: Ti⁴⁺
