The Periodic Table and Writing Chemical Formulas (Junior Cert Science): Model Answers

Sustaining Earth's Elemental Resources: Nitrogen, Helium, and Indium

Sample Answer

Question (a)

Answer

Nitrogen (N) is a gas which is a component of the Earth's atmosphere and is shown in the green category, indicating it is in plentiful supply.

Question (b)

Answer

Helium (He) should be avoided in birthday balloons because it is a limited, non-renewable resource that appears to be in shorter supply (yellow/orange category on the periodic table). Helium has essential uses in medicine (such as cooling MRI machines) and scientific research that cannot be substituted with other elements. Once released into the atmosphere from balloons, helium eventually escapes into space and is lost forever, making it unavailable for future critical applications.

Question (c)

Answer

To sustain indium levels for future generations, humans could implement comprehensive recycling programmes for smartphones and other electronic devices containing indium. By properly collecting, disassembling and processing used electronic devices, the indium can be recovered and reused in new products instead of being lost in landfills. Companies could also design phones with easier disassembly to facilitate the recovery of valuable elements like indium. Additionally, consumers could extend the useful life of their smartphones by keeping devices longer before upgrading, reducing the overall consumption rate of indium.

Marking Scheme