The noun 'rational' is a singular, common noun; a word for a number that can be written as a fraction or a ratio (rational number); a word for a thing.
The word 'rational' is also an adjective.
1.77 is a rational number
Very.
The noun 'whole' is a singular, common noun. The noun 'whole' is a concrete noun as a word for a thing in its complete form. The noun 'whole' is an abstract noun as a word for all of something.
The noun 'thing' is a singular, common noun. The noun 'thing' is a concrete noun as a word for a physical person, place, or object. The noun 'thing' is an abstract noun as a word for an idea, ability, or quality.
The fruit is a noun. The color can be a noun or an adjective.
"Rational" is an adjective and so there cannot be "a rational" (and certainly not "an rational"). Any answer would depend on whether the question was about a rational number, a rational person, a rational argument or "a rational" combined with some other noun.
Hypochondriac can be either a noun or an adjective. Examples: Jamie is a total hypochondriac. Nellie is basically rational, but she has hypochondriac tendencies.
Rational
1.14 is rational.
2020^2 = 400400 is a perfect square.......perfect square  noun Mathematics .1.a rational number that is equal to the square of another rational number.2.a polynomial that is the square of another polynomial.Origin:1935-40
4.6 is rational.
No, it is rational.
It is a rational number
It is rational. It is rational. It is rational. It is rational.
No, it is rational.
Rational.
It is rational