Answer: Rubidium has 5 orbits/shells/energy levels.
Explanation: It's electron configuration is as follows: 2-8-18-8-1.
The period of the wave is the reciprocal of its frequency.
1 / (5 per second) = 0.2 second .
The wavelength is irrelevant to the period. But since you
gave it to us, we can also calculate the speed of the wave.
Wave speed = (frequency) x (wavelength)
= (5 per second) x (1cm) = 5 cm per second
True. No matter can be created nor destroyed in pretty much every aspect of life, especially chemical reactions.
It confirmed medeleeve's hypothesis (prediction) and showed the use of his table
