I need help with this. part two n three in my profile

If the root word engage means “to connect with something,” what does the word disengage mean in the following sentence? he disengaged the gears by stepping on the clutch pedal.a.added more engine powerb.activated a connection to the pedalc.stalled the engined.released a connection to the pedal

How is the atomic number of a nucleus changed by alpha decay

Ascientist measures the speed of sound in a monatomic gas to be 449 m/s at 20∘c. what is the molar mass of this gas?