<span>Answer: O₃
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<span>Explanation:
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The term isoelectronic means same number of electrons.
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<span>Then you need to count the number of electrons in the given species NO₂⁻.
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<span>You have to count the number of electrons of N (nitrogen) atoms, the number of electrons of two O (oxygen) atoms, and the adjust for the negative charge of the ions.
</span><span>The atomic number of N is 7, meaning that each atom has 7 protons and 7 electrons.</span>
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The atomic number of O is 8, meaning that each atom has 8 protons and 8 electrons.
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<span>The negative charge of the ion means that it has one extra electron, which is the responsible for the negative charge.
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<span>Therefore the total number of electrons of the ion NO₂⁻ is 7 + 2 (8) + 1 = 24.
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<span>Note that that 24 = 3 x 8, so 24 is the number of electrons in 3 atoms of oxygen.
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<span>The moleucle O₃ is an allotrope of the oxygen. (an allotrope is a a form of an element with different structure and physical properties in the same physical state).
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<span>Therefore, the allotrope of oxygen isoelectronic with NO₂⁻ is O₃ (ozone)</span>
Answer:

Explanation:
Simply

Coal has two valent electrons, so there is 2 in 2p orbital
Answer:
D. TTACGCCAGG. that would be your answer.
Answer:
Yes
Explanation:
the gravity of an object depends on its mass. that's why the sun has its gravitational pull.
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