Chem chap #1

Chem chap #1

1. Chemistry

   • the study of the composition, properties, and interactions of matter
   • Domains
     • macroscopoic
       • the realm of everyday things that are large enough to be sensed directly by human sight or touch
     • microscopic
       • almost always visited in the imagination. Micro also comes from Greek and means “small.” Some aspects of the microscopic domains are visible through a microscope
     • symbolic
       • the specialized language used to represent components of the macroscopic and microscopic domains, such as chemical symbols
   • matter
     • anything that occupies space and has mass
     • States of matter
       • solid
         • something that is rigid and poseses a definite shape
       • liquid
         • flows and takes the shape of its container
       • gas
         • something that takes both the shape and volume of its container
       • plasma
         • A gaseous state of matter that contains an appreciable amount of electrically charged particles
     • mass
       • measure of the amount of matter in an object
     • weight
       • refers to the force that gravity exerts on an object
     • density
       • the ratio of the mass of a sample of the substance to its volume
     • Law of conservation of matter
       • There is no detectable change in the total quantity of matter present when matter converts from one type to another
     • element
       • a pure substance that CAN NOT be broken down into simpler substances by chemical changes
       • molecule
         • Consists of two or more atoms connected by strong forces known as chemical bonds. Can be made up of one element or multiple elements
       • atom
         • The smallest particle of an element that has the properties of that element and can enter into a chemical combination
       • compounds
         • Pure substances that CAN be broken down into simpler substances by chemical changes
       • mixtures
         • composed of two or more types of matter that can be present in varying amounts and can be separated by physical changes
         • Heterogeneous mixture
           • has a composition that varies from point to point
         • Homogenous mixture (aka solution)
           • exhibits a uniform composition and appears visually the same throughout
     • Properties
       • Physical
         • Physical Property
           • a characteristic of matter that is not associated with a change in its chemical composition
           • Physical change
             • a change in the state or properties of matter without any accompanying change in its chemical composition
       • Chemical
         • Chemical Property
           • The ability to change from one type of matter into another type (or the inability to change)
         • Chemical change
       • Intensive
         • Does not depend on the amount of matter present
       • Extensive
         • Depends on the amount of matter present
   • Dimensional Analysis
     • based on the premise: the units of quantities must be subjected to the same mathematical operations as their associated numbers