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Chapter 3: Chemical Foundations: Elements, Atoms, and Ions
I.
The elements
A. What is the most abundant element in the earth’s crust, oceans, and
atmosphere? Oxygen
B. Names and Symbols for Elements.
1.
What is an Element Symbol? An abbreviation for the element
a) Give 2 examples of symbols.
b) Why do some symbols not seem to match their element name?
(Fe = Iron) The symbol represents the Latin or Greek name.
2.
You must know the elements and symbols on table 3.4 on
page 57. You must also know.
Chlorine (Cl)
Fluorine (F)
Helium (He)
Hydrogen (H)
Iodine (I)
Iron (Fe)
Magnesium (Mg)
Tin (Sn)
II.
Atoms and Compounds
A. Dalton’s Atomic Theory
1.
Define the Law of Constant Composition: A given compound
always has the same composition.
2.
Dalton’s Atomic Theory has five parts. List them below.
a) Elements are made of tiny particles called ___atoms_______.
b) All atoms of a given element are ____Identical__________.
c) The atoms of a given element are ______Different from_____
those of any other element.
d) Atoms of one element can combine with atoms of other
elements to form Compounds.
A given compound always
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has the Same
relative numbers and types of
Atoms.
e) Atoms are not Created or Destroyed
in a chemical
reaction. A Chemical reaction simply changes
the way
the atoms are Grouped together.
B. Formulas of Compounds:
1. Define a Compound: A substance composed of 2 or more types of atoms.
2.
Define a Chemical Formula: An expression of the types of
atoms and quantity of each in a compound.
a) What is used to indicate the types of atoms in a formula? Symbols
b) What is used to indicate the quantity of each type of atom? Subscripts
c) In the formula for Ammonia (NH3).
i. What elements are present? Nitrogen and Hydrogen
ii. How many of each element is present? 1 Nitrogen and 3 Hydrogens
III.
Atomic Structure:
A. The Structure of the Atom:
1.
J.J. Thomson
a) What does “subatomic particles” mean? A particle that is
smaller than an atom and it is part of the atom.
b) What subatomic particle did J.J. Thomson discover? Electron
i. Describe that particle. Negative charged
c) What is the logic that Thomson used to predict a positive
particle? Atoms don’t have a charge. If an electron is negative, there
must also be a positive charged particle to cancel out the negative charge
so that the atom can be neutral.
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2.
Plum Pudding Model:
a) Describe the Plum Pudding model of the atom. An atom is a
positive sphere with negative electrons spread throughout.
3.
Earnest Rutherford:
a) Describe the experiment used by Rutherford to discredit the
plum pudding model. (a picture may help)
b) Describe Rutherford’s Nuclear Atom: An atom has a heavy
positive nucleus with electrons surrounding the neucleus.
c) What was the 1st subatomic particle that Rutherford
discovered? Proton
i. Describe that subatomic particle. Has a positive charge.
d) What was the second subatomic particle that Rutherford
Discovered? Neutron
i. Describe that subatomic particle. Does not have a charge it is neutral.
B. Modern Atomic Structure:
1.
Compare and contrast the 3 subatomic particle. Where is each
particle located in an atom, what is its charge and what how do the
masses compare to each other?
Location
Charge
Mass
Proton
In Nucleus
+1
Large
Neutron
In Nucleus
0
Large
Electron Surrounding the nucleus
-1
Very Small