<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.
Tt is the genotype that will appear in boxes two and three.
If you look at the column and row that intersect to form boxes two and three, you will see that they are T and t. That is the best way I can describe it, sorry if it’s confusing.
Answer: Heating the hydrated forms of cobalt chloride reverses the reactions above, returning cobalt chloride to the blue, water-free, or anhydrous, state. Water is "liberated" in these reactions, known as dehydration reactions.
Explanation:
The anion<span> is also </span>larger than<span> the </span>atom<span> because of </span>electron-electron repulsion<span>. As more </span>electrons are<span> added to the </span>outer shell<span>, and even to </span>higher<span> principle energy levels, the </span>repulsion<span> bewteen the negatively charged particles grows, pushing the </span>shells<span> farther from the nucleus.</span>
If the enthalpy change is negative, then the reaction is exothermic because heat energy was lost to the surroundings.
If the enthalpy change was positive, then the reaction was endothermic because heat energy was gained from the surroundings!
Hope this helps!! x