It is a liquid because when you have a liquid, there is no definite shape. Therefore, this would be the answer because it takes the shape of its container.
Final answer: a. Liquid
The given balanced reaction is,

The stoichiometric coefficients of each element or compound represents the number of moles of that element or compound required for the complete reaction to take place.
The mole ratios of different products and reactants will be:



So the mole ratio comparing iron (Fe) and oxygen gas (
) is
4 : 3
The answer is C. Isotopes.
Isotopes are defined as two substances that have the same number of protons and electrons, but a different number of neutrons, and therefore a different atomic mass. For example, carbon-12 and carbon-14 are isotopes of each other.
Hope this helps!
Foxes are warm blooded, so their bodies will cool themselves when they are overheating, Ectothermic animals, in other words cold blooded animals, have to find ways to cool themselves with water or shade, ect.