Isotopes and relative atomic mass

Which property is the same for ammonia molecules containing deuterium, $\ce{ND3}$, and ordinary ammonia molecules, $\ce{NH3}$? A. Molar mass B. Molecular geometry C. Density of the gas at STP D. Rate of diffusion

Naturally occurring gallium consists of two isotopes: 60 % of the atoms contain 38 neutrons and the remaining 40 % contain 40 neutrons. (i) Use section 7 of the data booklet to deduce the nuclear symbol of the heavier isotope. (ii) Calculate the relative…

Contrast the two isotopes in terms of atomic structure.

The sample produces the following mass spectrum. (i) Explain why the three peaks around $m/z$ 72 have different relative heights. (ii) From the sample, calculate the relative atomic mass of chlorine, giving your answer to two decimal places.

Heavy water, $\ce{^{2}H2O}$, boils at 101.4 °C, whereas ordinary water, $\ce{^{1}H2O}$, boils at 100.0 °C at the same pressure. Which statement is correct? A. The boiling points differ because $\ce{^{2}H2O}$ molecules have a greater mass, while the chemical…