The Nuclear Atom · Paper 1 — Free Chemistry HL Practice Questions

Lithium has atomic number 3. A sample contains two types of electrically neutral lithium atoms: one type has 3 neutrons and the other has 4 neutrons. Which statement correctly describes these two types of atom?

A sample of chlorine gas is analysed in a mass spectrometer, giving peaks at $m/z = 35$ (relative abundance 75.8%) and $m/z = 37$ (relative abundance 24.2%). The atomic number of chlorine is 17. How many neutrons are present in the lighter isotope?

Two atoms of neon each have 10 protons. One atom has 10 neutrons and the other has 12 neutrons. Which statement correctly describes the relationship between these two atoms?

A sample of potassium is analysed by mass spectrometry, giving two peaks: $m/z = 39$ (relative abundance 93.1%) and $m/z = 41$ (relative abundance 6.9%). The proton number of potassium is 19. How many neutrons are present in the isotope responsible for the peak at $m/z = 41$?