chapter 2 a&p

element

the simplest type of matter having unique chemical properties

atom

the smallest particle of an element that has the chemical characteristics of that element.

neutrons

no charge

protons

positive charge

electrons

negative charge

nucleus

formed by protons and neutrons

ionic bonding

atoms exchange electrons

covalent bonding

two or more atoms share electron pairs

ion

an atom loses or gains electrons and becomes charged

cation

positively charged ion

anion

negatively charged ion

molecules

two or more atoms chemically combine

electrolytes

solutions from dissociation of cations (+) and anions (-) in water

nonelectrolytes

solutions made by molecules that dissolve in water.

energy

the capacity to do work

potential energy

energy stored in chemical bonds

catalysts

substances that increase the rate of chemical reactions without being permanently changed or depleted

enzymes

a protein catalysts that increases the rate of chemical reactions

inorganic chemistry

usually, substances that do not contain carbon

acid

a proton donor

base

a proton acceptor

Four major groups needed for living things

carbohydrates, lipids, proteins, nucleic acids

amino acids

building blocks of proteins