What would be the correct grammar pattern for reffering to pieces of something (in a bowl/plate etc)?

e.g.: (referring to pieces of apples)

Are those apples? Sounds wrong to me.

Is that apple? This one sounds correct, as it refers to the class "apple," but this is for young learners EFL use, and the abstract notion of "class" may be too confusing.

Any ideas?

Thanks.
Equilibrium8pieces of something (in a bowl/plate etc)
Your examples have to do with apples, which are not pieces of something.

Are those apples? - Correct.

Is that apple. - No.

Is that an apple? - Correct.

CJ

(referring)
Thanks for your reply.

CalifJim
Equilibrium8pieces of something (in a bowl/plate etc)
Your examples have to do with apples, which are not pieces of something.
I mean as in pieces of apple (cut up) on a plate.