What chemical burns red?

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

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?

Why does earth rotate? because earth is formed from cold gases collapsing due to gravity because the matter in the nebula that formed earth was spinning because earth forms more than 99% of the mass of the solar system because the hydrogen atoms inside the nebula fused to form helium