Matter Everything is matter Matter is anything that

Matter • Everything is matter • Matter is anything that has mass and volume (occupies space)…matter can exist as a solid, liquid, gas, or plasma • Mass is the amount of matter that an object has • Volume is the amount of space an object takes up • MASS AND WEIGHT ARE NOT THE SAME!!!. . . why? • All matter, both living and non living, is composed of ATOMS

Atoms • All matter is composed of atoms • Atoms are the smallest particle of matter • They are the simplest part of an element that keeps all of the properties of the element it makes up • The different types of atoms determines how matter will be made up • The ancient Greeks said that matter must be made up of tiny particles they called “atomos” meaning “indivisible” • Atoms are extremely small…a teaspoon of water contains 500, 000, 000, 0 00 atoms

Elements • Elements are pure substances that cannot be broken down chemically into simpler kinds of matter • They are made of only one type of atom • There are over 100 known elements • Fewer than 30 are important to life • Over 90 percent of the mass of living things contains combinations of just four elements. They are Nitrogen, Oxygen, Carbon, and Hydrogen (CHON)

Molecules • A group of 2 or more atoms that are joined by a bond are called molecules • The smallest part of substances such as water, H 2 O, would be referred to as a molecule • Molecules may contain as few as two atoms, or as many as a million

• Most elements can interact with others to form compounds Compounds • all compounds are molecules but not all molecules are compounds • A compound is a molecule that contains two different kinds of elements • Remember that compounds are 2 different atoms joined by a bond • The properties of a compound are nothing like the elements that make it up

States of Matter • Matter is anything that has mass and volume • States of Matter are the different forms in which matter can exist • Matter exists in 4 states…solids, liquids, gases, and plasma…which is found inside stars • A solid holds a particular shape and has a definite volume…an orderliness exists to the particles of a solid • A liquid does not hold its own shape, but it does occupy a definite volume. It flows freely and takes the shape of its container • A gas has no definite shape or volume. It expands to fill available volume of its container

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1. In a gas the molecules are far apart and move at high speeds 2. In a liquid the molecules are more closely together, but still move rapidly; they slide over each other allowing them to pour 3. Solid molecules are held tightly together; they wiggle 4. Plasma is typically a gas that has lost electrons. Plasma is different from gases because of its unique properties. Plasma consists of a collection of free moving electrons and ions – (atoms that have lost electrons). With insufficient sustaining power, plasmas recombine into neutral gas. Plasmas are the most common state of matter in the universe

Changes in State • Now that we know that matter has different states, its time to learn what the process of changing state is called. • Melting is the process by which a substance changes from its solid state to its liquid state…the melting point is the temperature at which this happens • Boiling is the process by which a substance changes from its liquid state to its gaseous state by heating…the temperature at which this happens is its boiling point • Evaporation is a change from liquid to a gas without heating • Condensation is the process by which gases become liquids • Freezing is the process by which a liquid becomes a solid…the freezing point is the temperature it does this • Sublimation is the process of going from the solid state to the gas state…desublimation or deposition is the opposite of this

Pure Substances vs. Mixtures • • • Most substances we encounter are not chemically pure…air, cement, gasoline We can separate these substances into different pure substances Pure substances = matter with fixed composition and distinct properties…water, table salt, the elements…Pure substances can’t be broken down physically Substances are classified as either elements or compounds Elements cannot be decomposed into simpler substances…composed of only one kind of atom…they are pure substances Compounds are composed of two or more elements, containing two or more different kinds of atoms

Pure Substances vs. Mixtures • • • Mixtures are combinations of two or more substances…each substance retains its own chemical identity and its own properties Mixtures are different Coffee can be a little sweet or a lot…the substances making up a mixture (sugar, coffee, and water) are called components of the mixture Heterogeneous mixtures do not have the same composition throughout…sand, rocks, a salad. Can see it in appearance, properties, and compositions. Homogenous mixtures are those who are the same throughout. . . air, salt & water… also called solutions

Solutions • A solution is a type of mixture, a homogenous mixture • Sand in water is a mixture that is not a solution; Sugar in water can’t be identified as two separate substances, it is a solution • A solute is a substance that is dissolved to make a solution…the sugar • A solvent is the substance that dissolves the solute…water • Water is the most common and important solvent • Solutions don’t have to be made from a solid dissolved in a liquid…oxygen gas is dissolved in seawater; vinegar is acetic acid (liquid) in water • With two liquids, the substance that has the greater amount is the solvent • Two solids can also form solutions…tin + copper = bronze; Copper + Zinc = brass…these solid mixtures of metals are called alloys • The air we breathe is a solution of gases with nitrogen as the solvent • A mixture where the particles of a solute do not dissolve but make the solvent cloudy is called a suspension

Properties of Matter • Properties are characteristics that allow us to recognize a substance and to tell it apart from others • Physical properties are the characteristics of a substance that can be seen without altering the identity of the substance • Density, color, boiling point, hardness, and melting point are examples of physical properties • Chemical properties are the characteristics of a substance that cannot be observed without altering the substance…they describe the way a substance may change or react to form other substances • Flammability is a chemical property…the ability of a substance to burn in the presence of oxygen; rusting; radioactivity • Properties can be extensive (depends on how much you have) or intensive (doesn’t depend on how much)

Changes in Matter • Physical changes involve the changing of a substance without altering its identity…appearance changes without changing composition • Crushing and tearing are physical changes as well as changes in state • Chemical changes, or chemical reactions, reactions do alter the identity of a substance • A piece of wood undergoes chemical changes as it burns • Food changes when it cooks • Metal changes when it rusts • Signs of a chemical change include: Production of odor, change in temperature, change in color, production of bubbles (gas), formation of a solid (precipitate)

Properties of Matter • We can identify substances and separate the components of a mixture by taking advantage of their different properties • To identify unknowns, use properties like melting pt. , density, heat properties, solubility, electric properties, and magnetic properties. • You can separate based on appearance, magnetism, filtration, distillation, density, melting pt. , or solubility • Properties of a compound are nothing like the properties of the atoms that make them up

Conservation of Matter • Matter, like energy, is neither created nor destroyed in any process • This is the Law of Conservation of Matter • In every reaction there is an equal quantity of matter before and after • Explained by Antoine Lavoisier, a French scientist also called “the father of modern chemistry” • Matter can also be converted to energy E=mc 2