A mole is the number of grams of a substance that equals its molecular (or atomic) mass in daltons. There are 6.02×10²³ molecules (or atoms) in 1.0 mole (Avogadro's number; see Concept 3.2 ). The data table shows the "molar ratios" of some of the products from the Miller H₂S experiment. In a molar ratio, each unitless value is expressed relative to a standard for that experiment. Here, the standard is the number of moles of the amino acid glycine, which is set to a value of 1.0 . For instance, serine has a molar ratio of 3.0×10⁻² , meaning that for every mole of glycine, there is 3.0×10⁻² mole of serine. (a) Give the molar ratio of methionine to glycine and explain what it means. (b) How many molecules of glycine are present in 1.0 mole? (c) For every 1.0 mole of glycine in the sample, how many molecules of methionine are present? (Recall that to multiply two numbers with exponents, you add their exponents, to divide them, you subtract the exponent in the denominator from that in the numerator.)