The value of γ( = Cp/Cv), for hydrogen, helium and another ideal diatomic gas X (whose molecules are not rigid but have an additional vibrational mode), are respectively equal to,
1
\(\frac{5}{3}, \frac{7}{5}, \frac{7}{5}\)
2
\(\frac{7}{5}, \frac{5}{3}, \frac{7}{5}\)
3
\(\frac{7}{5}, \frac{5}{3}, \frac{9}{7}\)
4
\(\frac{5}{3}, \frac{7}{5}, \frac{9}{7}\)