what type of polynomial is 5x^y?

its binomial right?

how many terms do you see? 1

how many wheels on a bicycle? 2
how many lenses in a monocle? 1

The expression is a monomial.

A binomial has two terms, which are separated by a + or - sign

Actually, 5x^y is not even a polynomial. It is an exponential function of x and y.

Polynomials have constant values for exponents. For example,

5 x^2 y (monomial)
3xy^3 + xy^2 (binomial)