Thermal energy travels<span> by conduction, convection, and radiation. It occurs when a cooler and warmer object touches each other. </span>
<h2>Answer:</h2>
Compound. Option A is correct
<h2>Explanations:</h2>
When two or more different elements combines, a compound is formed. For instance, if carbon and oxygen combines, carbondioxide is formed according to the equation;

From the reaction, carbon and oxygen are the elements while carbondioxide is the compound. Hence we can conclude that a pure substance formed when two or more different elements combine called compound.
Yes. Mercury has 80 protons. Tin has 50 protons. Same for electrons, it just doesn't have an exact number.
An aqueous solution of hydrozen chloride: Strongly corrosive acids
A colouriess punpent liquid widely used in manufacturing plastic and pharmaceutical
<span>The water cycle has no starting point. But, we'll begin in the oceans, since that is where most of Earth's water exists</span>