Lynn English High School Science Ms. Mezzetti Modified from Modern Biology Textbook-Holt

Define the term matter. Explain the relationship between elements and atoms. Draw and label a model of the structure of an atom. Explain how compounds affect an atom’s stability. Contrast covalent and ionic bonds.

Matter is anything that occupies space and has mass. Mass is the quantity of matter an object has.

Elements are made of a single kind of atom and cannot be broken down by chemical means into simpler substances. Atoms are composed of protons, neutrons, and electrons.

The Nucleus Protons and neutrons make up the nucleus of the atom. Protons are positively charged particles. Neutrons have no charge (neutral).

Electrons –Electrons move about the nucleus in orbitals. –An orbital is a three- dimensional region around a nucleus that indicates the probable location of an electron.

Isotopes Atoms of the same element that have a different number of neutrons are called isotopes.

Ionic Bonds –An ionic bond is formed when one atom gives up an electron to another. The positive ion is then attracted to a negative ion to form the ionic bond.

Objectives Describe the physical properties of each state of matter. Describe the role of reactants and products in chemical reactions.

Energy and Matter States of Matter –Addition of energy to a substance can cause its state to change from a solid to a liquid and from a liquid to a gas.

Energy and Chemical Reactions Reactants are substances that enter chemical reactions. Products are substances produced by chemical reactions.

Objectives Identify the roles of solutes and solvents in solutions. Differentiate between acids and bases.

Solutions Solute + Solvent = Solution

Acids and Bases Acids –Acidic solutions contain more hydronium ions than hydroxide ions. Bases –Basic solutions contain more hydroxide ions than hydronium ions. Buffers –Buffers are chemicals that neutralize the effects of adding small amounts of either an acid or a base to a solution.

pH –Scientists have developed a scale for comparing the relative concentrations of hydronium ions and hydroxide ions in a solution. This scale is called the pH scale, and it ranges from 0 to 14.

Name 3 parts of an atom What are 3 states of matter Differentiate covalent and ionic bonds What makes up a solution Differentiate reactants and products Why is pH important to living organisms