The answer to the problem is 100
Answer:
<h2>Oxygen has six valence electrons, two in the 2s subshell and four in the 2p subshell.</h2>
<h3>Valence electrons are the electrons in the outermost shell, or energy level, of an atom. </h3>
<h3>Configuration of oxygen's valence electrons as 2s²2p⁴.</h3>
Explanation:
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Answer: C
Explanation:
In endothermic reactions, enthalpy is positive, and in exothermic reactions, enthalpy is negative, So, if enthalpy is positive, then it is an endothermic reaction, and hence is required for the reaction to occur.