<u>Ans: 650 J = 155 calories</u>
<u>Given:</u>
Energy in joules = 650 J
<u>To determine:</u>
The energy in calories
<u>Explanation:</u>
1 joule = 0.2388 calories
Therefore, 650 joules = 0.2388 calories * 650 J/1 J = 155 calories
Answer:B) a reactant that undergoes reduction
Explanation:
Oxidation reaction is defined as the reaction in which a substance looses electrons. The oxidation state of the substance increases during oxidation.
Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced during reduction.

Overall reaction: 
The substance M which itself gets oxidized, reduces other and is called as reducing agent. The substance N which itself gets reduced, oxidizes other and is called as oxidizing agent.
a. ELEMENT: A substance<span> that </span>cannot<span> be decomposed (</span>broken down<span>) </span>into simpler substances by ordinary chemical<span> means.</span>