Because there is no such thing as a perfectly efficient machine, some energy is always transformed into undesirable forms. In the case of lightbulbs, engines, and any object with moving parts - this “undesirable” form of energy is __ energy.

This chart lists four kinds of polymers and their sources. what can be known about all four polymers, despite their differences? they come from living things. they share ionic carbon bonds. they are at least 100 monomers long. they are made of repeating subunits.

The number at the end of an isotope’s name is the number.

What is the percentage of hydrogen in c2h4