CHEM 111 Study Guide - Fall 2018, Comprehensive Midterm Notes - Periodic Table, Hydrogen, Carbon
12 Oct 2018
School
Department
Course
Professor
CHEM 111
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Chem 111
Sept 7th
Chapter 1: Matter on the Atomic Scale
● The properties of matter depend on the types and arrangements of atoms and molecules
Classification of matter:
● Either substances or mixtures
● Substances can either be elements or compounds, via chemical reactions
● Mixtures can either be homogeneous mixtures (solutions) or heterogeneous mixtures
Elements
● Most basic units of matter
● Composed of only one type of atom
● Can’t be broken down into smaller units by chemical means
● Simple definition: things found on the periodic table
● Ex: Sodium (Na), dihydrogen (H_2), iron (Fe)
● 118 elements on table, 90 naturally occurring ones
● Diatomic elements: H, N, O, F, Br, I
Atoms Vs Molecules
● Atoms: the smallest chemical unit of matter or indivisible unit of an element (ex. H, O,
Na)
● Molecule: more than one atom with same or different atoms combined (ex. O is an atom,
O_2 is a molecule b/c atom + atom)
Compounds :Combination of at least two or more atoms of different elements bonded together
in a defined ratio
● Can be broken down into smaller units by chemical means
● All compounds are molecules, but not all molecules are compounds (ex. O_ 2 and N_2
are molecules and not compounds)
● Ex: sugar (C_6_H_12_O_6), Sand (SiO_2)
States of Matter
● The physical states of a substance can be interconverted to one another by the addition
or removal of energy
● The state is called “phase” such as the “liquid phase”
● Physical changes do not alter the chemical composition of the substance (you don’t
change the structure of molecules, you change the space/interaction between them)
● In general, macroscopic properties of these states are directly related to the
arrangement and properties of particles at the atomic level
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Pure Substances: A collection of matter that has the same chemical composition throughout
● Can consist of a single element or compound
● Have unique physical properties
● Cannot be separated to individual species by physical techniques
Chemical Change: involves a change in the chemical composition of the material
● Ex. iron turning to rust in the presence of air, combustion of hydrogen, Combustion of
Methane
Physical properties
● Boiling point
● Melting point
● Density
● Color
● Condensation
● Evaporation
● Dissolving
Chemical properties
● Reacting with other compounds/ molecules
● combustion/ burning in air
Mixtures: Matter containing two or more substances that are present in variable amounts and
have not reacted chemically.
● Can be homogeneous or heterogeneous
Homogeneous mixtures: mixtures that have a constant composition throughout the material.
● Uniform and consist of a single phase
● Referred to as Solutions
Heterogeneous mixture: a mixture in which the composition is not uniform
● Consists of more than 1 phase
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
The properties of matter depend on the types and arrangements of atoms and molecules. Substances can either be elements or compounds, via chemical reactions. Mixtures can either be homogeneous mixtures (solutions) or heterogeneous mixtures. Composed of only one type of atom. Can"t be broken down into smaller units by chemical means. Simple definition: things found on the periodic table. Ex: sodium (na), dihydrogen (h_2), iron (fe) 118 elements on table, 90 naturally occurring ones. Diatomic elements: h, n, o, f, br, i. Atoms: the smallest chemical unit of matter or indivisible unit of an element (ex. Molecule: more than one atom with same or different atoms combined (ex. O_2 is a molecule b/c atom + atom) Compounds :combination of at least two or more atoms of different elements bonded together in a defined ratio. Can be broken down into smaller units by chemical means. All compounds are molecules, but not all molecules are compounds (ex.
