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26 terms

Biology Chapter 2.1 and 2.2- The Chemistry of Life

STUDY
PLAY
atom
the basic unit of matter
nucleus
the center of the atom which contains the protons and neutrons; the structure in cells that holds the cell's genetic material (DNA) and controls the cell's activities
electron
negatively charged particle; located outside the atomic nucleus
element
substance consisting entirely of one type of atom
isotope
atom of an element that has a number of neutrons different from that of other atoms of the same element
compound
substance formed by the chemical combination of two or more elements in definition proportions
ionic bond
bond formed when one or more electrons are transferred from one atom to another
ion
atom that has a positive or negative charge
covalent bond
bond formed by the sharing of electrons between atoms
molecule
smallest unit of most compounds
van Der Waals forces
a slight attraction that develops between the oppositely charged regions of nearby molecules
cohesion
attraction between molecules of the same substance
adhesion
attraction between molecules of different substances
mixture
material composed of two or more elements or compounds that are physically mixed together but not chemically combined
solution
mixture of two or more substances in which the molecules of the substances are evenly distributed
solute
substance that is dissolved in a solvent to make a solution
solvent
substance in which a solute is dissolved to form a solution
suspension
mixture of water and nondissolved materials
pH scale
measurement system used to indicate the concentration of hydrogen ions (H+) in solution; ranges from 0 to 14
acid
compound that forms hydrogen ions (H+) in solution
base
compound that produces hydroxide ions ( OH+ ) in solution
buffer
weak acid or base that can react with strong acids or bases to help prevent sharp, sudden changes in pH
KEY POINT # 1
The subatomic particles that make up atoms are PROTONS, NEUTRONS, ELECTRONS
KEY POINT # 2
Because they have the same # of electrons, all isotopes of an element have the same chemical properties
KEY POINT # 3
The main types of chemical bonds are IONIC BONDS AND COVALENT BONDS
KEY POINT # 4
A water molecule is polar because there is an uneven distribution of electrons b/w the oxygen and hydrogen atoms