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.
4.6 is rational.
No, it is rational.
It is rational. It is rational. It is rational. It is rational.
It is a rational number
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
No, it is rational.
Rational.
It is rational