Chapter 6: The Chemistry of Life Ch. 6.1 Atoms & Their Interactions Both living and nonliving things are composed of the same basic building blocks called atoms. Elements Element- a substance that can't be broken down into simpler chemical substances. On Earth, 90 elements occur naturally Natural elements in living things- Only about 25 of 90 elements are essential to living organisms. Each element is identified by a one or two letter abbreviation ex: C - carbon Trace elements- …showed first 75 words of 372 total…

…showed last 75 words of 372 total…share electrons Molecules- a group of atoms held together by covalent bonds and having no overall charge For example: water H2O has two Hydrogen atoms and one Oxygen atom How ionic bonds form- An atom (or group of atoms) that gains or loses electrons has an electrical charge Ion- a charged particle Ionic bond- the attractive force between two ions of opposite charge Ionic bonds are less abundant in living things than covalent molecules