Term | Definition |
Activation Energy | What is needed to start a chemical reaction. |
Arrow(-->) | You read the arrow as "yields" in a chemical equation formula. |
Characteristics of a Chemical Reaction | Changes in energy or change in properties. Examples bubbles burning etc. |
Chemical Change | Alter the chemical properties of matter; new substances with new properties are formed. |
Chemical Equations | A shorter and easier way to show chemical reactions by using symbols instead words. |
Coefficient | A number placed in front of a chemical formula in an equation. Tells you how many atoms or molecules of each reactant must equal the total mass of the products. |
Conservation of mass | The amount of matter involved in a chemical reaction does not change. The total mass of the reactants must equal the total mass of the products. |
Controlling rates of reaction | concentration, temperatures, surface area, catalysts, enzymes inhibitors |
Decomposition Reaction | A compound breaks down into simpler substances. |
Endothermic Reactions | An observable change in energy that shows a chemical reaction took place; A reaction that takes heat from the solution, absorbs energy, makes it feel cooler. |
Exothermic Reaction | An observable change in energy that shows a chemical reaction took place; that releases heat ; gives off energy, makes it feel warmer most chemical. |
Physical Changes | Alter only the physical properties of matter; no new substance are formed. Can be a change in size shape or color; change in phase. |
Precipitate | A solid that forms from solutions during a chemical reaction; observable change that shows a chemical reaction took place. |
Products | The material you have after a chemical reaction; written on the right side of the formula. |
Reactants | The materials you have at the beginning of a chemical reaction; written on the left side of the formula. |
Replacement Reaction: | One part of a compound is displaced by an element or compound from another substance (also called displacement reaction) |
States of Matter (pp. 46-50): | solid, liquid, and gas |
Subscripts: show the number of atoms of an element in a molecule or the ratio of elements in a compound. | Show the number of atoms of an element in a molecule or the ratio of elements in a compound. |
Synthesis Reaction: | Two substances combine to form a new compound (also called composition reaction) |