Most of the mass of an atom is contained in its
Atomic mass is determined by the number of neutrons plus
The number of protons in an atom determines the
Atoms are electrically ________ because they have the same number of protons and electrons.
The principal elements found in living things are carbon, hydrogen, oxygen, and
the smallest complete unit of a compound or diatomic gas
a new substance formed by the combination of two or more different atoms
area that electrons are found around an atomic nucleus
The atomic mass of an element whose atoms consist of eight protons, nine neutrons, and eight electrons is:
how many elements have been identified?
When an atom ____ an electron, it becomes charged.
An atom that has gained or lost electrons is called an ___
____ is produced when an acid reacts with a base.
The reactivity of an atom is due to the number and arrangement of ______ in the outer energy level.
The bond that includes sharing electrons with another atom is called
When an atom loses an electron, it becomes _______ charged
Atoms which transfer electrons can combine to form a(n) _______ bond.
_________ _______ are the result of an atom attempting to rearrange its configuration to result in a stable octet.
Water can dissolve only _______ compounds.
are compounds that produce H+ ions in solution. A substance which yields an anion plus a proton is a(n)
When atoms combine, interactions occur between their
The bonds that link many water molecules together to form a water drop are _______. The weak type of bonding which attracts molecules to molecules is ______.
When electrons are shared, the type of bonding is called
The heat needed for chemical reaction to take place is called
A substance that helps a reaction to take place, but does not participate in the reaction is called a
H2CO3 ------> H2O + CO2
NH3 + H2O -------->NH4OH occurs when a molecule is formed from the bonding of atoms, ions or simpler molecules.
H2SO4 + 2KOH --------->K2SO4 + 2H2O reaction occurs when the bonds of the reacting compounds are broken and new combinations are formed. Acid + base yields salt + water
Substances which maintain a body's pH within narrow limits are called
What is expected when reactants break bonds?
decomposition using water. Carbohydrates are converted to energy by the process of ________.
Polysaccharides are ______ sugars
Of the three liquid types, _________ are more similar to fats
The ___ bases are attached to the phosphate part of the structure.
carry the genetic codes which determine the structure and function of an organic compound
Lipids are chemically most similar to
In a protein molecule, the number of amino acid molecules may be as many as:`
Enzyme, antibody, hormone, and muscle are roles played by
The largest molecules in organisms are
How many electrons does carbon lack in its outer shell?
When compounds which are formed from _____ bonds decompose, the products are usually ions of the original elements
Large organic molecules which are synthesized from multiple identical subunits are carbohydrates, proteins, nucleic acids, and _______
Amino acids are the building blocks of
Carbon forms ______ bonds.
The largest organic molecules are _______ ____
Protein catalysts which cause reactions to occur at temperatures and pH values which are common to living cells are called _______. Are produced within an active cell. An organism can NOT live without ______. A catalyst for chemical reactions in biological systems is called an _______.
Nonprotein substances (such as vitamins and some metal ions) which need to be present for enzymes to function are called
A sugar or polymer of sugar.
A group of organic compounds including fats, steroids, and phospholipids.
A sequence of sugars, phosphates and nitrogenous organic bases: DNA and RNA.
A chemical compound in which each molecule is made up of two or more simpler molecules strung together.
A reaction in which two or more molecules unite, forming a more complex molecule.
A large complex organic molecule consisting of a large number of amino acids linked together by peptide bonds.
an acid located in the cell nucleus