if two hybrid parents mate, what chance is there that their offspring will also be a hybrid?

Question

1. 0%
2. 25%
3. 50%
4. 100%

Answer 1

If you mean hybid in the sense of heterozygous, it's (3), 50%. Draw the Punnett Square for Aa x Aa and examine the offspring:

. . . A . . a
A . AA . Aa
a. . Aa . aa

You have two true-breeding offspring and two heterozygous offspring: 2/4 or 50% are hybrids.

If on the other hand you mean hybrid as in a cross of two separate species, in most (animal) cases, the parents will not produce any offspring. Cross-species hybrid males are generally sterile, while the females can only breed with a non-hybrid.

(By the way, the series of questions you just asked probably belong in Biology, not Chemistry.)

Answer 2

4.

Answer 3

3. 50%
AB + AB → AA + AB + BA + BB
AB + AB → AA + 2AB + BB
2/4 = 50%