Scientists of the 19th Century Found That the Equation, 1

Multiple Choice

Scientists of the 19th Century found that the equation, 1/ l = R_H(1/n²₁ - 1/n²₂) (where R_H = 1.097×10⁷ m ^{- 1}, and n₁ and n₂ are whole numbers) predicts the wavelength of the lines in the emission spectrum of the H atom. This equation is properly referred to as:

A) a theory
B) a postulate
C) a law
D) a hypothesis
E) none of these