Assume that an electron orbits around a nucleus in a circular orbit, and Newton's laws are valid. What is the ratio of the kinetic energy \((KE)\) of the electron to its potential energy \((PE)\) in orbit (in magnitude)?
1. \(1:2\)
2. \(2:1\)
3. \(1:1\)
4. none of the above

A hydrogen ion and a singly ionised helium atom are accelerated from rest through the same potential difference. The ratio of their final speeds is close to:
1. \(1:2\)
2. \(10:7\)
3. \(5:7\)
4. \(2:1\)