Scientists believe that the modern horse developed from a short, horse-like mammal about the size of a dog. Over millions of years, the horse increased in size and developed much longer legs. Horses with longer legs had a better chance of surviving than the shorter-legged members of the herd. How did longer legs help horses survive? A. They allowed the horses to reach nuts in trees.

B. They allowed the horses to outrun predators.

C. They allowed the horses to carry more body weight.

D. They allowed the horses to capture prey.

Pretty sure it's B. cause I remember doing this

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !