Chapter 1: Matter and Change Chemistry is a Physical Science Matter and Its Properties Elements

Chemistry is a Physical Science

What is chemistry? The study of the composition  What is it? structure  How is it put together? and properties  How does it behave? of matter and the changes it undergoes.

6 branches of chemistry List on page 6 1. Organic-study of carbon-containing compounds. 2. Inorganic-study of anything inorganic. 3. Physical-study of the properties & changes of matter & their relation to energy 4. Analytical-the identification of the components & composition of materials. 5. Biochemistry-study of substances and processes occurring in living things. 6. Theoretical-understanding chemical behavior & predicting properties of new substances.

Matter and Its Properties

What is matter? All matter has two properties in common:  Volume-the amount of 3D space an object occupies  Mass-a measure of the amount of matter present. Anything that has mass and takes up space is matter.

Remember! Atom-the smallest unit of an element that maintains the properties of that element Element-a pure substance made of only one kind of atom  Found on the periodic table Compound-a substance made from the atoms of two or more elements that are chemically bonded

Properties and Changes in Matter Extensive property-depends on the amount of matter that is present  Ask, “If I double the amount of matter that I have, will this property change?” If yes, then the property is extensive.  Examples-mass and volume

Properties and Changes in Matter Intensive property-does not depend on the amount of matter present  Ask, “If I double the amount of matter that I have, will this property change?” If the answer is no, then intensive property.  Examples-color, boiling point, and density

Extensive or Intensive? Examples:  boiling point  volume  mass  density  conductivity intensive extensive intensive

Properties and Changes in Matter Physical property-a characteristic that can be observed or measured without changing the identity of the substance.  Examples-melting & boiling points Physical change-a change in a substance that does not involve a change in the identity of the substance.  Examples-grinding, cutting, and boiling

Changes of State Change of state-a physical change of a substance from one state to another  Three common states of matter are solid, liquid, and gas.  Any change of a substance between these state is a PHYSICAL change!

States of Matter Solids  very low KE - particles vibrate but can’t move around  fixed shape  fixed volume

States of Matter Liquids  low KE - particles can move around but are still close together  variable shape  fixed volume

States of Matter Gases  high KE - particles can separate and move throughout container  variable shape  variable volume

Fourth State of Matter Plasma  very high KE - particles collide with enough energy to break into charged particles (+/-)  gas-like, variable shape & volume  stars, fluorescent light bulbs

Properties and Changes in Matter Chemical property-a characteristic that can NOT be observed without changing the identity of the substance.  Example-ability of charcoal to burn in air Chemical change-a change in which one or more substances are converted into different substances.  AKA chemical reaction  reactants  products  Examples-Charcoal burning in air

Property or Change? Physical or Chemical? Examples:  flammable  burning of a log  magnetic  ice melting  tarnishes in air  melting point  iron rusting  grinding spices  Property, chemical  Change, chemical  Property, physical  Change, physical  Property, chemical  Property, physical  Change, chemical  Change, physical

Classification of Matter MATTER Can it be physically separated? Homogeneous Mixture (solution) Heterogeneous MixtureCompoundElement MIXTUREPURE SUBSTANCE yesno Can it be chemically decomposed? noyes Is the composition uniform? noyes Figure 1-8, page 15

Pure Substances Element  Composed of identical atoms  On the periodic table  Examples-copper wire, aluminum foil Compound  Composed of 2 or more elements in a fixed ratio  Properties differ from those of individual elements  Example-table salt (NaCl)

Mixtures Variable combination of 2 or more pure substances. Heterogeneous- not uniform composition Homogeneous- uniform composition AKA solutions

What type of matter is it?  graphite (form of carbon)  pepper  sugar (sucrose)  paint  soda element hetero. mixture compound hetero. mixture solution