Final answer:
To achieve the desired properties, include GaAs in the alloy for conductivity and the presence of a band gap, but add a corrosion-resistant metal to resist corrosion.
Step-by-step explanation:
In order to determine the composition of a GaAs gap alloy that will meet each criteria, we need to understand the properties of GaAs and how they can be modified.
A) To conduct electricity, we need a material that is either a conductor or a semiconductor. GaAs is a semiconductor, so we can include it in the alloy to ensure conductivity.
B) Ferromagnetism is not a property of GaAs, so we cannot achieve it by modifying the alloy composition.
C) Having a band gap is inherent to semiconductors like GaAs. So, including GaAs in the alloy will maintain the presence of a band gap.
D) GaAs is susceptible to corrosion, so adding a metal that is resistant to corrosion, such as gold or platinum, as an alloy component can help resist corrosion.