How long until you can swim after a belly button piercing?

In a good thermo flask the main cause of heat loss is

Exercise 2. find the wavelength of a photon emitted when an electron jumps from the n = 3 energy level down to the n = 2 energy level. where is this photon in the electromagnetic spectrum?

Amagnetic field applies forces on: a)static chargesb)moving chargesc)water flow