When an ionic compound dissolves like salt, what breaks apart from each other in the water? (not ions)

Why is it important always to use horizontal bars in unit fractions when performing unit conversions?

Gordon is going for a run through the park, but it is cold outside. the low outside temperature could affect his personal safety.

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?