<span>When a chemical reaction occurs and the thermometer in the container records a drop in temperature t</span>he reaction is exothermic because heat was released by the reaction.
<span>B. The reaction is exothermic because heat was released by the reaction. is your answer.
Hoped I helped!</span>
Answer:
Two water molecules contain 4 hydrogen atoms and 2 oxygen atoms. A mole of water molecules contains 2 moles of hydrogen atoms and 1 mole of oxygen atoms.
Explanation:
When the neutrons and electrons are the same. For example, sodium (Na) has an atomic mass of 11, meaning it has 11 protons and 11 electrons etc.