A metal sphere, mounted on an insulating stand, is negatively charged.
State the name of the SI unit used to measure electric charge.
A smaller, initially uncharged metal sphere, also on an insulating stand, is brought close to the negatively charged sphere without making contact.
Describe how the charge distributes itself on this smaller metal sphere.
While the smaller sphere is still near the negatively charged sphere, an earthed metal wire is briefly touched against the side of the smaller sphere furthest from the charged sphere. State and explain what happens to the charge on the smaller sphere.
Explain, in terms of their atomic-level structures, why the metal wire is an electrical conductor but the plastic stand is an electrical insulator.
145 exam-style questions on CIE IGCSE Physics 4.2.1a Positive and negative charge. Each one has a worked solution and a mark scheme showing where the marks go.