Introductory Chemistry: Matter and Energy

Mark S. Cracolice Edward I. Peters www.cengage.com/chemistry/cracolice Chapter 2 Matter and Energy Mark S. Cracolice The University of Montana Copyright ©2016 Cengage Learning. All Rights Reserved. Course Learning Outcomes CLO 1.3 – Describe the Kinetic Molecu...

Mark S. Cracolice Edward I. Peters www.cengage.com/chemistry/cracolice Chapter 2 Matter and Energy Mark S. Cracolice The University of Montana Copyright ©2016 Cengage Learning. All Rights Reserved. Course Learning Outcomes CLO 1.3 – Describe the Kinetic Molecular Theory CLO 2.1 – Discuss the states of matter CLO 2.2 – Describe the Chemical and Physical Properties of Matter Copyright ©2016 Cengage Learning. All Rights Reserved.  Matter Mass: a piece of material that occupies a volume or space. Everything that has mass is matter Macroscopic: Consideration of matter on a scale observable by the human eye Geologists study matter at this level Microscopic: Consideration of matter on a scale observable with a classic microscope Microbiologists study matter at this level Particulate: Matter on a level too small to be observable with the human eye or microscope Needs to be modeled Copyright ©2016 Cengage Learning. All Rights Reserved. Atoms and Molecules Atom - Smallest particle of an element Can combine with atoms of other elements to form chemical compounds Molecule - Smallest unit particle of a pure substance Can exist independently and possess the identity of the substance Represented by a chemical symbol Example: H represents a hydrogen atom, O represents an oxygen atom H2O - Chemical formula of water (states that one molecule of water consists of two hydrogen atoms and one oxygen atom) Copyright ©2016 Cengage Learning. All Rights Reserved. Model A representation of something Chemists use models of atoms and molecules that are based on experimental data H2O - Chemical formula of water (states that one molecule of water consists of two hydrogen atoms and one oxygen atom) Common molecular model Ball-and-stick: Three- dimensional representation of a molecule that uses balls to represent atoms and sticks to represent electron pairs Copyright ©2016 Cengage Learning. All Rights Reserved. States of Matter In gas, particles move fast and far apart, overcome attractive forces In liquid, molecules touch one another and move freely among themselves In solid state, molecules vibrate in fixed positions Crystalline solid: Solid in which molecules are arranged in a definite pattern Amorphous solid: Solid which lacks pattern in its particle arrangement Copyright ©2016 Cengage Learning. All Rights Reserved. States of Matter Differences among solids, liquids, and gases can be explained in terms of kinetic molecular theory Kinetic molecular theory: All matter consists of extremely tiny particles that are in constant motion Kinetic - Motion Molecular – pertaining to molecule’s Molecules are attracted to one another The speed at which particles move is faster at higher temperatures and slower at lower temperatures Copyright ©2016 Cengage Learning. All Rights Reserved. Properties and Changes Physical properties: Characteristics that can be observed and measured without altering the identity of the substance Physical change: Changes that occur in the form of a substance without changing its chemical identity Chemical change: Chemical identity of a substance is destroyed and a new substance forms (old bonds break; new bonds form) Known as chemical reaction Chemical properties: All chemical changes possible for a substance Copyright ©2016 Cengage Learning. All Rights Reserved. Conclusion Get started on your in-class quiz. You have up to 2 attempts, in which your highest attempt will be your final score. Password: kinetic Please do not hesitate to reach out to me via email.Be sure to thoroughly revise the chapter, as well as view the supplemental videos via Brightspace. Homework 2 is open, as always HomeWorks are unlimited attempts, and is due Sunday, at/by 11:59pm. Copyright ©2016 Cengage Learning. All Rights Reserved.