Atomic structure and isotopesEdexcel A-Level Chemistry: Mind map

Exam questions on Atomic structure and isotopes

1. Sulfur has several naturally occurring isotopes, including ³²S and ³⁴S (atomic number 16). A technician is studying a sample of sodium sulfide, which contains the sulfide ion ³⁴S²⁻.
   Explain why ³²S and ³⁴S have the same chemical properties but different masses.2 marks
2. A physics teacher describes the sodium ion ²³Na⁺ (atomic number 11) to a class using the relative mass and relative charge of the three sub-atomic particles.
   Deduce the total relative charge of the ²³Na⁺ ion and its approximate relative mass. Explain why the electrons can be ignored when finding the relative mass.2 marks
3. Chlorine exists naturally as two isotopes, ³⁵Cl and ³⁷Cl (atomic number 17). A student studies the chloride ion ³⁷Cl⁻ and a chlorine molecule in which one atom is ³⁵Cl and the other is ³⁷Cl.
   State the number of protons, neutrons and electrons in one ³⁷Cl⁻ ion.3 marks