Unit 1: (1)Classification of Matter Physical Science PSc.2.1 Understand types, properties, and structure of matter.

Classifying Matter Matter is……… anything that has mass and takes up space made up of atoms NOT matter: Light, Sound, and Electricity

Classification of Matter Matter is usually categorized by make-up and/or composition. Things are grouped together that have certain similarities. Classification – grouping things together based on similarities. Matter can be classified as: Pure substance Mixture

Pure Substances and Mixtures Always has same composition Every sample of a given substance has the same properties because a substance has a fixed, uniform composition. Can be classified into two categories: Elements and Compounds Mixtures Made of 2+ substances Mixed together physically but not chemically (think of lemonade).

Pure Substances Sugar cannot be broken into other substances by physical means; only by chemical changes.

Other Pure Substances Salt, a compound Gold, an element These substances are all elements or compounds. They have fixed compositions, which means they never change. These are pure substances. Water, a compound Chromium, an element

Elements Elements Simplest pure substance. Cannot be broken down into any simpler substance. Example: oxygen, nitrogen, carbon, etc. Atom = smallest particle of element. Atoms of different elements are different. There are about 115 known elements at this time. 92 occur naturally; the rest were made in laboratories.

Symbols Chemical symbols Shorthand way to write the name of an element. One or two letters. First letter always capitalized. Second letter lowercase. Most symbols come from the element’s English name. A few come from the element’s Latin name.

Elements & Symbols 2nd

Elements & Symbols The symbols of the following elements come from their English name: Oxygen (O) Lithium (Li) Strontium (Sr) Nickel (Ni)

Elements & Symbols The symbols of the following elements come from their Latin name: Iron (Fe: Latin name = Ferrum) Gold (Au: Latin name = Aurum) Potassium (K: Latin name = Kalium) Lead (Pb: Latin name = Plumbum)

Compounds Two or more elements Chemically combined in a fixed proportion Pure substances Each particle or unit of a compound is exactly alike Can be broken down into elements by chemical means only. Ex. Sodium Chloride = sodium + chloride

Compounds Have diff. properties from the elements that make them up. Example: Hydrogen is an extremely flammable gas. Oxygen supports burning. Together they make water, which is not flammable and does not support burning. Water has different properties from the elements that make it up.

Chemical Formulas Chemical formula Formula for water = H2O Shows the ratio of each element present. Formula for water = H2O Understood 1 behind the O 2 atoms of hydrogen (H) to 1 atom of oxygen (O)

Chemical Formulas Formula for calcium nitrate = Ca(NO3)2 When a formula has parentheses, the number after the parentheses multiplies everything inside. 1 atom of calcium (Ca) 2 atoms of nitrogen (N) 6 atoms of oxygen (O)

Mixtures Tend to retain some of the properties of their individual substances Properties can vary because the composition of a mixture is not fixed Can be classified by how well the parts of the mixture are distributed throughout the mixture. Can be homogenous or heterogeneous

Mixtures Heterogeneous- parts of the mixture are noticeably different Example: Sand, chocolate chip cookie These are also called suspensions when they separate from one another. These are substances you must shake before using. Example: Salad dressing

Mixtures Homogeneous- “same”; not able to distinguish the individual components These are also called solutions Ex: swimming pool, stainless steel (mixture of iron, chromium, and nickel), sweet tea.

Solutions, Suspensions, and Colloids The size of the particles in a mixture has an effect on the properties of the mixture. Based on the size of its largest particles, a mixture can be classified as a solution, a suspension, or a colloid.

Solutions (homogenous mixture) Solutions have 2 parts: A. Solute- what you are adding to be dissolved; the part that is being dissolved B. Solvent- what is being used to dissolve something else. Water is the “universal solvent” Example: Kool-aid

Suspensions (heterogeneous mixture) Separates into layers over time. Made of larger particles that can scatter light in all directions. Sometimes appear to look cloudy. Ex: salad dressing, sand and water, blood and plasma.

Colloid- contains medium sized particles that scatter light Does NOT separate into layers Example: Fog, milk, whipped cream

Review _____________________ is the study of matter and how it changes. _____________ Anything that has mass and takes up space Ex: desk, books, air, water ______________ Combination of more than one pure substance ______________ _ (solution) a mixture that looks the same throughout ex: air, salt water, gasoline ________________ A mixture that shows different parts Ex: pizza, sand, salad dressing, oil and water Separates into layers over time Ex: sand and water Has particles intermediate in size Ex: fog, smoke _______________ Matter that has a fixed composition Can be found on the Periodic Table Ex: carbon (C); hydrogen (H) Substance of more than one element bonded together Ex: water (H2O); salt (NaCl); carbon dioxide (CO2)

CHEMISTRY is the study of matter and how it changes. Anything that has mass and takes up space Ex: desk, books, air, water MIXTURE Combination of more than one pure substance HOMOGENEOUS (solution) a mixture that looks the same throughout ex: air, salt water, gasoline HETEROGENEOUS A mixture that shows different parts Ex: pizza, sand, salad dressing, oil and water _SUSPENSION__ Separates into layers over time Ex: sand and water COLLOID Has particles intermediate in size Ex: fog, smoke PURE SUBSTANCE Matter that has a fixed composition ELEMENT Can be found on the Periodic Table Ex: carbon (C); hydrogen (H) COMPOUND Substance of more than one element bonded together Ex: water (H2O); salt (NaCl); carbon dioxide (CO2)