Summary CHM 1025 Exam 1 Study Guide

Chemistry Exam 1 Study Guide (Chapters 1-4)

Chapter 1: Matter and Energy

1.1 Matter and its Classification:
 Matter- anything that occupies space and has mass.
 Mass- a measure of the quantity if matter.
 Pure Substance- matter that has the same chemical composition no matter what its
origin.
o Elements and Compounds
 Mixture- a combination of two or more substances that can vary in composition.
o Separation of mixtures is physical using procedures such as grinding,
dissolving, or filtering.
 Homogeneous Mixture- a combination of two or more substances that has uniform
composition.
o Solution- a homogeneous mixture of two or more substances
uniformly dispersed at a molecular of ionic level.
 Heterogeneous Mixture- a combination of two or more substances that is not uniform
throughout.
 Element- a substance that cannot be broken down into simpler substances even by a
chemical reaction.
o Metal- an element characterized by luster and the ability to conduct
electricity. Ex: Copper(Cu), Aluminum(Al), Iron(Fe)
o Nonmetal- an element that usually has a dull appearance and is a poor
conductor of electricity. Ex: Carbon(C), Chlorine(Cl), Sulfur(S)
 Compound- a substance composed of two or more elements combined in definite
proportions.
 Chemical Formula- describes the composition of a compound, using the symbols for
the elements that make up the compound.
 Atom- the smallest unit of an element that has the chemical properties of that
element.
 Molecule- two or more atoms bound together in a discrete arrangement.
 Aqueous Solution- a homogenous mixture of two or more substances in which the
solvent is water.

Physical States of Matter

,1.2 Physical and Chemical Changes and Properties of Matter:
 Physical Property- a characteristic of a substance that can be observed without
changing its composition.
o Ex: odor, taste, hardness, mass, volume, density, magnetism,
conductivity, temperature, color, shape, texture, physical state
 Chemical Property- a characteristic of a substance defined by its composition and the
chemical changes it can undergo.
o Ex: burning, rusting, digesting
 Density- The ratio of the mass of a substance to its volume.
o Density = mass/volume
 Physical Change- a process that changes only the physical properties of a substance,
not its chemical composition.
 Chemical Change/Chemical Reaction- a process in which one or more substances are
converted into new substances that have compositions and properties different from
those of the original substances.


Metric Conversions

, 1.3 Energy and Energy Changes:
 Energy- the capacity to do work or to transfer heat.
 Work- the action of a force over a distance.
 Kinetic Energy- the energy possessed by an object because of its motion.
o Ex: wheelbarrow rolling down a ramp
 Potential Energy- the energy possessed by an object because of its position.
o Ex: wheelbarrow resting at the top of the ramp




1.4 Scientific Inquiry:
 Scientific Method- a method of inquiry or investigation that involves cycles of
observation and interpretation.
 Hypothesis- a tentative explanation for the properties or behavior of matter that
accounts of a set of observations and can be tested.