Explain why the speed of light decreases when it moves from air to glass, and why gamma rays are not affected by electric and magnetic fields.

Here are the solutions to the questions:

أ) علل (Explain/Give reasons):

1. تقل سرعة الضوء عند انتقاله من الهواء إلى الزجاج (The speed of light decreases when it moves from air to glass).

   • The speed of light in a medium is inversely proportional to its refractive index. Glass has a higher optical density and thus a higher refractive index than air, causing light to slow down when it enters glass.

2. أشعة غاما لا تتأثر بالمجال الكهربي والمجال المغناطيسي (Gamma rays are not affected by electric and magnetic fields).

   • Gamma rays are a form of electromagnetic radiation consisting of photons, which have no electric charge and no rest mass