Substance a is a solid ionic compound substance b solid covalent compound what would happen if you put them both in the same container

How have the competing explanations' experiments on atoms affected the development of the atomic model?

Idon’t quite understand this problem

The charge on an electron is 1.60218 × 10−19 c and its mass is 9.10939 × 10−31 kg. how strong a magnetic field must be experienced by the electron if its path is a circle of radius 5.5 cm? answer in units of t.