The most coenmon isotope of oxygen has an atomic mass of 1 6 ( 1 6 O ) . An isolepe with an alomic mass of 1 8 ( 1 5 O ) is also stable. How many valence electrons are present in ” O ? the same as in 1 6 O more than in 1 4 O Never of the other answer options is correct. fewer than 1 6 O
Answer
Valence Electrons in Isotopes of Oxygen
Oxygen (symbol: O) typically has the atomic number 8, which means it has 8 protons and, in a neutral atom, also 8 electrons. Valence electrons are the electrons in the outermost shell, and for oxygen, this is 6 valence electrons in its 2nd shell (2s²2p⁴).
Isotopes of oxygen, such as 16O, 17O, and 18O, differ in their number of neutrons, not electrons or protons.
✅ The same as in 16O
✔️ All stable oxygen isotopes (including 18O and 17O) have 8 electrons, so they all have the same number of valence electrons: 6.
✔️ All stable oxygen isotopes (including 18O and 17O) have 8 electrons, so they all have the same number of valence electrons: 6.
❌ More than in 16O
✘ Isotopes do not gain electrons with added neutrons; valence electrons remain unchanged.
✘ Isotopes do not gain electrons with added neutrons; valence electrons remain unchanged.
❌ Fewer than 16O
✘ Again, fewer neutrons doesn’t affect the electron configuration of the neutral atom.
✘ Again, fewer neutrons doesn’t affect the electron configuration of the neutral atom.
❌ Never of the other answer options is correct
✘ This is grammatically incorrect and factually wrong based on atomic structure.
✘ This is grammatically incorrect and factually wrong based on atomic structure.
📘 Conclusion:
Isotopes of an element differ only in the number of neutrons. The number of valence electrons depends solely on the atomic number (i.e., the number of protons/electrons), which does not change between isotopes. Therefore, all neutral oxygen isotopes have 6 valence electrons.
Isotopes of an element differ only in the number of neutrons. The number of valence electrons depends solely on the atomic number (i.e., the number of protons/electrons), which does not change between isotopes. Therefore, all neutral oxygen isotopes have 6 valence electrons.