Atoms, Molecules, Chemical Elements, Isotopes, Atomic Number, Atomic Weight, Electron Shells, Valence, Ions, Ionic Bonds, Covalent Bonds, Hydrogen Bonds, Chemical Reactions, Endergonic and Exergonic Reactions, Synthesis, Decomposition, Exchange Reactions,

Atoms, Molecules, Chemical Elements, Isotopes, Atomic Number, Atomic Weight, Electron Shells, Valence, Ions, Ionic Bonds, Covalent Bonds, Hydrogen Bonds, Chemical Reactions, Endergonic and Exergonic Reactions, Synthesis, Decomposition, Exchange Reactions, Inorganic Compounds, Water as Solvent and Reactant, pH, Acids, Bases, Salts, Buffers, Organic Compounds, Carbon Skeletons, Functional Groups, Monomers, Polymers, Carbohydrates, Lipids, Proteins, Amino Acids, Nucleotides, DNA, RNA, ATP, Energy Metabolism, Oxidation-Reactions Exam Questions Verified and Provided with A+ Graded Rationales Latest Updated 2026 chemistry science of the interaction between atoms and molecules what does metabolic activities of microorganisms involve complex chemical reaction microbes break down nutrients to obtain energy and to make new cells atom is the smallest unit of chemical element that exhibits the properties of that element what does an atom consist of a nucleus, which contains protons and neutrons and electrons which move around the nucleus atomic weight atomic # is the # of protons in the nucleus, the total # of protons and neutrons chemical element are atoms with same # of protons and the same chemical behavior chemical symbols are chemical elements designated by abbreviations 26 elements are commonly found in living cells isotopes are atoms that have the same atomic # (are of the same elements) but different atomic weights in an atom electrons are arranged around the nucleus in electron shells chemical properties of an atom are due largely to the # of electron in its outermost shell compounds are molecules made up of two or more atoms; molecules consisting of at least two different kinds of atoms atoms form molecules in order to fill their outermost electron shells chemical bonds are attractive forces that bind the atomic nuclei of two atoms together combining capacity of an atom is the number of chemical bonds the atom can form with other atoms-is its valence ion positively or negatively charged atom or group of atoms ionic bond a chemical attraction between ions of opposite charge to form an ionic bond one ion is an electron donor and the other ion is an electron acceptor in a covalent bond are atoms share pairs of electrons covalent bonds are stronger than ionic bonds and are far more common in organisms hydrogen bond exists when a hydrogen atom covalently bonded to one oxygen or nitrogen atom hydrogen bonds form weak links between different molecules or between parts of the same large molecule molecular weight is the sum of the atomic weights of all the atoms in a molecule a mole of an atom, ion, or molecule is equal to its atomic or molecular weight expressed in grams chemical reactions are the making or breaking of chemical bonds between atoms chemical reaction a change of energy occurs endergonic reactions require more energy than they release; exergonic reactions release more energy synthesis reaction atoms, ions or molecules are combined to form a larger molecule decompostion reaction a larger molecule is broken down into its component molecules ions or atoms exchange reaction two molecules are decomposed and their subunits are used to synthesize two new molecules. original reactants are products of reversible reactions can readily revert to form inorganic compounds