... room temperature and pressure, both hydrogen and oxy-gen are gases. But water under the same conditions is a liquid. If it gets a few tens ofdegrees colder, water turns solid at standard pressure. ... of juice,” and the supply of chemical energy must be restored bycharging. Some cells and batteries, such as lead-acid car batteries, can be rechargedby driving current through them, and others, ... is equal to one thousand volts (1,000). One megavolt (MV)is equal to one million volts (1,000,000) or one thousand kilovolts.In a dry cell, the EMF is usually between 1.2 and 1.7 V; in a car...