Lynn English High School ScienceMs. MezzettiModified 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 NucleusProtons 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.

IsotopesAtoms 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 ChemicalReactions

•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 (H+)

• Bases– Basic solutions contain more hydroxide ions than

hydronium ions (OH-)• 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 atomWhat are 3 states of matterDifferentiate covalent and ionic bondsWhat makes up a solutionDifferentiate reactants and productsWhy is pH important to living organisms