Presentation on theme: "ANYTHING WITH MASS AND VOLUME. Matter Pure Substances Mixtures Elements Compounds Homogeneous Heterogeneous Draw this chart!, leave space to define the."— Presentation transcript:
ANYTHING WITH MASS AND VOLUME
Matter Pure Substances Mixtures Elements Compounds Homogeneous Heterogeneous Draw this chart!, leave space to define the terms
Pure Substances vs. Mixtures A pure substance is made of only one kind of material and has definite properties. Matter that consists of two or more substances mixed together but not chemically combined is called a mixture.
Pure Substances: Elements are the simplest pure substance. –Examples: hydrogen, carbon, and oxygen. The smallest particle of an element that has the properties of that element is called an atom.
Pure substances: Compounds are pure substances that are made of more than one element bound together. –Examples: water (H 2 O), and carbon dioxide. A molecule is formed when two or more atoms chemically combine. Example: water (H 2 O), O 2
MIXTURES Heterogeneous vs. Homogeneous Homogeneous matter (solutions): matter that has identical properties throughout. Heterogeneous matter: matter that has parts with different properties. Examples: salt water, gravy, whipped cream Examples: granite, soil, potpourri, cookies
LIQUID MIXTURES Miscible vs. Immiscible Miscible Mixture: liquids that mix evenly, forming a homogeneous solution. Example: Soda mixed with Koolaid Immiscible Mixture: liquids that DO NOT mix evenly, forming a heterogeneous mixture. Example: Oil mixed with Water
EXAMPLES What type of matter are each of the following… ?
Pure Substance: COMPOUND
Homogeneous mixture of: Nitrogen, N % Oxygen, O % Argon, Ar 0.93% Carbon dioxide, CO % Neon, Ne % Helium, He % Methane, CH % Krypton, Kr % Nitrogen(I) oxide, N 2 O % Hydrogen, H % Xenon, Xe % Ozone, O % Many gases make up mixture, but it looks like it is all one gas.
Pure Substance: ELEMENT: Au
Homogeneous mixture of copper and tin (alloy: mixture of metals)
Conservation Law of Conservation of Mass: Mass cannot be created or destroyed. Law of Conservation of Energy: Energy cannot be created or destroyed; it may only change from one form to another.
Matter and Energy MUST be conserved is the LAW!
Virtually everything is made up of atoms.
From the very large...
To the very small...
We are all made of atoms…and only atoms. This includes you and me! Giggitty, Giggitty, Goo!
The Elements Song Currently we have about 117 kinds of atoms. In the natural world there exists 92 different kinds of atoms. The others have been artificially produced in laboratories.
We call each kind of atom an element, and give it a specific name and symbol. Copper Cu Gold Au
Abundance of the elements, by weight
The Earths interior is rich in iron
Sand is made of Silicon & Oxygen
The ocean waters are made of oxygen & hydrogen
Atoms are made up of protons, neutrons, and electrons. Protons and neutrons are found in the nucleus of atoms -- roughly at the center Electrons travel around the nucleus. Of course real atoms dont look anything like this you imbecile!
Different kinds of atoms, or elements, are different because they have different numbers of protons. It would be sweet if atoms really were this huge!
We list the elements by their atomic numbers - the number of protons they have. Hydrogen, number 1 Helium, number 2 In several cases the atomic weights are in parentheses. This indicates that these elements have no stable isotopes; that is, they are radioactive. The value enclosed in parentheses and used for the atomic weight is the atomic mass number of the most stable known isotope, as indicated by the longest half-life.
Physical Properties Physical properties: characteristics that can be observed without changing the identity of the substance. Examples: –mass –volume –color –shape –texture –density
Physical Changes Physical change: a change in the physical form or properties of a substance that occurs without a change in composition. Examples: –melting –freezing –grinding –dissolving
Chemical Properties Chemical property: describes a substances ability to change into a different substance. Examples: –flammability –reactivity
Chemical Changes Chemical change: occurs when a substance changes composition by forming one or more new substances. (bonds are broken and bonds are formed) Example: –HCl + NaOH NaCl + H 2 O
Indications of a Chemical Change… Heat in Endothermic (feels cold) Heat out Exothermic (feels hot) Gas is given off (fizzing or bubbles) Color Change New Substance is Formed
Evaporation is a physical change
Breaking is a physical change.
Boiling is a change of state, and therefore a physical change!
Rusting is a Chemical Change
Burning is a Chemical Change
Kinetic Theory All matter is made of atoms and molecules that act like tiny particles. These tiny particles are always in motion. The higher the temp., the faster the particles move. At the same temp., more massive (heavier) particles move slower than less massive (lighter) particles. (inertia)
SOLIDS Definite shape? YES Definite volume? YES Molecules in a solid are tightly packed and constantly vibrating. Eureka: Molecules in Solids
LIQUIDS Definite shape? NO Definite volume? YES Some liquids flow more easily than others. The resistance of a liquid to flow is called viscosity. –Honey has a high viscosity compared to water. Eureka: Molecules in Liquids
GASES Definite shape? NO Definite volume? NO The particles in a gas are spread very far apart, but can be compressed by pumping them into a restricted volume. Eureka: Molecules in Gases
Phase Changes (Changes of State) Changes in phase are examples of physical changes. Melting: solid liquid Freezing: liquid solid Vaporization: liquid gas Condensation: gas liquid Sublimation: solid gas Deposition: gas solid
Changes of State GAS SOLID Deposition Sublimation Vaporization Condensation Melting Freezing LIQUID Melting
ENERGY is the ability to change or move matter. Energy is ABSORBED when substances melt or evaporate. –NOTE: our bodies cool down when our sweat evaporates. Energy is RELEASED when substances freeze or condense. Energy Transfers
Melting The change of state from solid to liquid. Energy (heat) is absorbed by the substance that is melting.
Freezing The change of state from liquid to solid. Opposite of melting. Energy (heat) is released by the substance undergoing freezing.
Evaporation The change of state at the surface of a liquid as it passes to a vapor. This results from the random motion of molecules that occasionally escape from the liquid surface. –Energy (heat) is absorbed by the liquid –Can happen at any temperature
Condensation The change of state from gas to liquid. The opposite of evaporation. –Energy (heat) is released by the gas to become a liquid.
Boiling Change from state from a liquid to a gas. Occurs throughout the liquid. –boiling point/temperature is determined by pressure –Energy (heat) is absorbed by the liquid for it to boil and produce gas.
*Boiling & freezing points depend on the pressure.
Water at normal pressure (1 atm): For water at normal (every day) pressures: Melting/freezing point: Condensing/boiling point: 0 o C (32 o F) 100 o C (212 o F)
*Boiling & freezing points depend on the pressure. 0 °C 100°C