I need help plz physics

What structural formula represents 4 electrons shared between two atoms?

Wavelength of 125 meters is moving at a speed of 10 m/s. what is it's frequency?

The amount of heat required to change liquid water to vapor at its boiling temperature is 2256 kj/kg. the amount of heat required to change liquid mercury to its vapor state at its boiling temperature is 295 kj/kg. one kg of each substance is currently at its boiling point. how will the amount of thermal energy required to change each substance from a liquid to a gas differ?