1 Flashcards
What is a chemical reaction?
A change in which one or more pure substances are converted into different pure substances with different properties.
What is a reactant?
A starting pure substance in a chemical reaction.
What is a product?
A pure substance formed in a chemical reaction.
What is a precipitate?
A solid that separates from a solution.
What is a chemical symbol?
A representation of an element using letters.
What is a chemical formula?
A representation of the composition of a substance using chemical symbols and numeric subscripts.
What is a subscript?
A whole number that appears to the right and below a chemical symbol in a chemical formula (if no number is written it is assumed to be ‘1’).
What is a chemical equation?
A representation of the reactants and products in a chemical reaction.
What is a word equation?
A chemical equation in which the reactants and products in a chemical reaction are represented by words.
What is a formula equation?
A chemical equation in which the reactants and products in a chemical reaction are represented by chemical symbols or chemical formulas.
What is an atom inventory?
A ‘bookkeeping’ technique designed to count the number of each type of atom (ion) represented on each side of a chemical equation.
What is a coefficient?
A whole number that appears in front of a reactant or product in a balanced chemical equation (if no number is written it is assumed to be ‘1’).
What is a balanced chemical equation?
A formula equation where coefficients are added so equal numbers of each type of atom (ion) are represented on each side of the equation.
What is the Law of Conservation of Mass?
Mass is neither created nor destroyed during ordinary chemical and physical changes.
What is an atom?
The smallest particle of an element that retains the chemical properties of that element.
What is a catalyst?
A substance that increases the rate of a chemical reaction without being permanently changed.
What is an ionic formula?
A chemical formula representing the types and numbers of ions in a formula unit.
What is a formula unit?
The smallest electrically neutral collection of positive and negative ions (anions and cations) in an ionic compound.
What is a molecular formula?
A chemical formula representing the types and numbers of atoms combined in a single molecule.
What is a molecule?
A neutral group of atoms held together by covalent bonds which acts as an independent unit capable of existing on its own.
What is a synthesis reaction?
A chemical reaction in which two or more reactants combine to produce one new product.
What is a decomposition reaction?
A chemical reaction in which one reactant decomposes (breaks-up) into two or more simpler products.
What is a single-replacement reaction?
A chemical reaction in which one element replaces a similar element in a compound to produce a new element and a new compound.
What is a double-replacement reaction?
A chemical reaction in which the ions of two compounds exchange places in an aqueous solution to produce two new compounds.
What is a combustion reaction?
A chemical reaction in which a substance reacts with oxygen releasing a large amount of energy in the form of heat and light.
What is reaction rate?
The rate (speed) of disappearance of a reactant or the rate of appearance of a product in a chemical reaction.
What is concentration?
A measure of the number of particles of matter per unit volume.
What is temperature?
A measure of the average kinetic energy of the particles in a sample of matter.
