Presentation on theme: " Matter- anything that has mass and volume Atom- smallest unit of an element that keeps the properties of element Element- pure substance made of."— Presentation transcript:
Matter- anything that has mass and volume Atom- smallest unit of an element that keeps the properties of element Element- pure substance made of only one type of atom Compound- substance made of 2 or more types of atoms that are chemically bonded Molecule- type of compound in which bonds are covalent bonds
Particles of matter are ALWAYS in motion. The kinetic energy (speed) of these particles increases as temperature increases.
chemists use characteristic properties to tell substances apart and to separate them some properties define a group of substances
Extensive- depend on the amount of matter Ex: volume, mass, amount of energy Intensive- do not depend on the amount Ex: density, boiling point, ability to conduct
Physical- characteristics that can be observed or measured without changing the identity of a substance Chemical- relates to a substances ability to undergo changes that transform it into a different substance Easiest to see when a chemical is reacting
definite volume definite shape Particles are rigidly held in fixed positions strong attractive forces between atoms only vibrate in place
definite volume indefinite shape atoms are close together atoms can overcome attractive forces to flow
indefinite volume indefinite shape atoms move very quickly atoms are far apart pretty weak attractive forces high compressibility
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 ColloidsSuspensions
Element composed of identical atoms EX: copper wire, aluminum foil
Compound composed of 2 or more elements in a fixed ratio properties differ from those of individual elements EX: table salt (NaCl)
Law of Definite Composition A given compound always contains the same, fixed ratio of elements. Law of Multiple Proportions Elements can combine in different ratios to form different compounds.
For example… Two different compounds, each has a definite composition.
Variable combination of 2 or more pure substances. HeterogeneousHomogeneous
Solution homogeneous very small particles no Tyndall effect Tyndall Effect particles don’t settle EX: rubbing alcohol
Examples: graphite pepper sugar (sucrose) paint soda element hetero. mixture compound hetero. mixture solution