Matter: States and Properties

What is matter? Matter is anything that has mass and volume (takes up space.)

What is a physical property? A physical property is something that can be observed or measured without changing the matter’s identity. Some physical properties of matter include: mass, weight, volume, density, color, and odor.

What is mass? What is volume? Mass is the amount of matter in an object. Volume is the amount of space a object takes up.

Weight is the pull of gravity on the mass of an object. What is weight? Weight is the pull of gravity on the mass of an object.

What is density? Density is the amount of mass in a given space or volume. D= M/V What has more density: a pound of feathers or a pound of lead? or

Why do liquids of different densities form layers? The densest layer is also the heaviest…it settles on the bottom. Other layers appear in the order of most dense to least dense. Molasses

What are the three main states of matter? A state is a physical form. Matter is commonly either a solid, a liquid or a gas, the three common states of matter.

Solids have definite shape and volume. What is a solid? Solids have definite shape and volume. Two types of solids are: Amorphous: its particles are not arranged in a pattern. Crystalline: its particles have an orderly repeating pattern

Amorphous form Solids

Crystalline form Solids

What is a liquid? State of matter that changes shape but not volume. Liquids take the shape of their container.

What is the container in these photos of a liquid? Water

State of matter that changes both shape and volume. What is a gas?   State of matter that changes both shape and volume. Particles spread out as far as container will allow.

Gas nebulas

What is plasma? Plasma is superheated gas Plasma can create electrical and magnetic fields.

Sun with solar flares (plasma)

Solar flares (plasma)

Changes in Physical Properties

How does one state of matter become another? Matter changes state because of changes in temperature and pressure

Ways Matter Changes State: Melting Melting is the change from a solid to a liquid state Takes place at the melting point Particles move faster Endothermic reaction

Ways Matter Changes State: Freezing Freezing is the change from a liquid to a solid state Takes place at the freezing point Particles slow down Energy removed Exothermic reaction

Ways Matter Changes State Evaporation Evaporation is the change from liquid to gas Evaporation happens at the surface of a liquid *not the same as boiling, which occurs all through the liquid

Ways Matter Changes State Boiling Boiling is the change from liquid to gas Boiling takes place throughout the liquid Occurs when the vapor pressure equals the atmospheric pressure boiling and melting points are the same for any substance Changes with elevation

Ways Matter Changes State Condensation Condensation occurs when a gas changes state to a liquid The condensation point is the temperature and pressure that the gas changes to a liquid. Same temperature as boiling point Condensation is the reverse of evaporation

Ways Matter Changes State Sublimation Sublimation is the change from solid directly to gas Endothermic reaction where energy is gained as it changes state Examples: dry ice and snow packs can sublimate without going through the liquid state

Changes in Chemical Properties

What is a chemical property? A chemical property is any characteristic that gives a substance the ability to undergo a change that results in a new substance. Example: A match burns and becomes ash.

What is a chemical property? Chemical properties describe what chemical changes can occur Flammability: the ability to combust or burn Reactivity: the ability to combine with other substances

What is a chemical change? When substances change into new substances that have different properties.

Examples of chemical changes Sour milk

Rocket engines

Rust

Other Examples of Chemical Changes Include the: combustion (burning) of wood, metabolism of food in the body, mixing an acid and a base such as hydrochloric acid (HCl) and sodium hydroxide (NaOH), cooking an egg, digesting sugar with the amylase in saliva, mixing baking soda and vinegar to produce carbon dioxide gas, baking a cake, electroplating a metal or using a chemical battery!

How do you know if a chemical change has occurred? Signs of a chemical change: 1. Change in odor 2. Heat is released or cooling occurs 3. Sound or light 4. Color 5. Fizzing and foaming

Mixtures and Compounds

What is a mixture? A mixture is a combination of two or more substances that are not chemically combined Examples: Cowboy pizza (pepperoni, sausage and Canadian bacon) Chorizo Omelette Peanut Butter Sandwich

How do you separate a mixture? Distillation Separates based on different boiling points Evaporation Removal of water Filtration Screening out larger particles Physical Methods Pick out the different substances

What is a compound? A compound is a pure substance made up of two or more elements that have been chemically combined

What is the difference between Mixtures and Compounds? Elements combine chemically Elements become new substance with different properties Elements cannot be separated Mixtures: elements mixed, not chemically combined Elements keep their individual properties Elements can be separated

A solution is a mixture that appears to be a single substance What is a solution?   A solution is a mixture that appears to be a single substance Particles are evenly distributed among each other Solutions may be liquids, gasses

What is an atom? An atom is the smallest particle into which an element can be divided and still be the same substance. Atoms are composed of even smaller particles

Parts of the Atom: Protons are in the nucleus (center) of the atom. Protons have a positive charge Proton have much of the mass in an atom

Parts of the Atom: Neutrons are also in the nucleus of the atom. Neutrons have no charge Neutrons are also about as massive as protons

Parts of the Atom: Electrons are outside the nucleus of the atom are. Electrons have a negative charge Electrons have very small mass, only about 1/1800 of a proton.

What are the properties of elements? Elements are made up of a single type of atom. Their properties include: Density, or mass/volume Melting Point, the temperature of a solid changes to liquid Conductivity, the ability to carry electrons. Hardness, or how resistant to scratching a substance is Color, determined by what wavelengths of light are absorbed

How are elements classified? Metals: Found to the left of the zig zag line on periodic table Most elements are metals Most are solid at room temperature Have few electrons in outer levels

How are elements classified? Nonmetals: Found to the right of zig zag line Many are gasses at room temperature Have nearly complete set of electrons in outer levels.

How are elements classified? Metalloids: Found on border of the zigzag line on the periodic table Have about half the electrons in outer levels. Have some properties of both metals and nonmetals

The mass number is the total number of protons and neutrons in an atom What is a mass number? The mass number is the total number of protons and neutrons in an atom

What is atomic mass? Some elements occur with different numbers of neutrons and have different masses The atomic mass is the average weighted mass of all naturally-occurring isotopes of an element.

What is an isotope? An isotope is a form of an element that has a different number of neutrons than protons Isotopes are often unstable and radioactive.

How are elements arranged? Elements are arranged in groups in the Periodic Table Periodic table elements repeat in a pattern of every 7 elements Pattern was observed by Mendeleev, who developed the periodic table

How is the Periodic Table arranged? Periods Periods are horizontal rows on the periodic table. Physical and chemical properties repeat in a pattern Slowly change as you move across the row.

How is the Periodic Table arranged? Groups Columns on the periodic table are called groups. Elements in the same group same number of electrons in their outer shells They have like properties

How is the Periodic Table arranged? Families Families are groups Families have similar properties and are grouped together in columns on the periodic table Examples: Alkali metals Alkaline-earth metals Transition metals boron group and carbon group Noble gases

How do different elements combine to form substances? Bonding Bonding holds two atoms together Chemical bonds are formed when atoms electrons are shared, gained or lost

How do different elements combine to form substances? Valence electrons Electrons in the outermost energy level Only electrons used in chemical bonding Come in sets of 8

How do different elements combine to form substances? Ions Atoms that have lost or gained an electron are ions. Metals are likely to loose electrons and become positively-charged ions Non-metals are likely to bond with metals

What is an ionic bond?   Ionic bonds hold compounds together with the force of attraction between positive and negative charges The number of electrons lost by a positive ion equals the number of electrons gained by the negative ion

What is an ionic bond? http://bcs.whfreeman.com/thelifewire/content/chp02/02020.html

What is a covalent bond? Covalent bonds form when atoms in a compound share one or more electrons. Covalent bonds result in low melting and boiling points. Molecules created from covalent bonds are often brittle as solids.

What is a covalent bond? http://bcs.whfreeman.com/thelifewire/content/chp02/02020.html