Because the colour of a "negative wire casing" is black, hence the reason why negative numbers were written in this colour :)
Any positive number can be written as a quotient of two positive numbers or a quotient of two negative numbers. Any real number can be written as the quotient of two real numbers.
12.04 is rational. Rational numbers are numbers that can be written as a fraction. Irrational numbers cannot be expressed as a fraction.
-010010001(not repeating) is rational. Rational numbers are numbers that can be written as a fraction. Irrational numbers cannot be expressed as a fraction.
Yes, except for zero. Numbers larger than 1 have positive exponents, and numbers between 0 and 1 have negative exponents. Negative numbers would just have a '-' in front.
No. Whole numbers are counting numbers and zero.