Transcript Lesson 14 Atoms, Elements & the Mole

Lesson 14 Atoms,
Elements & the Mole
Objectives
*
The student will define an element.
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The student will define and explain the
parts of an atom.
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The student will convert between names
and symbols for commonly used
elements.
*
The student will define a mole, and
explain what it is used for.
Standard Deviants
 Tape 1 IB The ELEMENTS
I.
Atoms, elements, names, and symbols.
“Atom” comes from Greek for indivisible
The atom is recognized as the fundamental unit
of matter
Atoms contain smaller parts, known as protons,
neutrons, and electrons
a.
b.
c.
i.
ii.
iii.
Protons are subatomic particles with a charge of +1, a
mass of 1 atomic mass unit (AMU), and are found in the
nucleus of an atom.
Electrons are subatomic particles with a charge of –1,
a mass which is approximately 1/1800th that of a proton
(and therefore usually considered to have zero mass),
and are found in the space outside the nucleus of an
atom.
Neutrons are subatomic particles with no charge, a
mass of one atomic mass unit (AMU), and are found in
the nucleus of an atom.
iv. Drawing of atomic model:
d. Variations
i. Each element has a unique number of protons
ii. Electrons are arranged differently depending
on the atom
iii. Different forms of the same element can have
different numbers of neutrons
e. The properties of elements vary
i. They vary in a pattern
ii. When organized by this pattern, they form the
“periodic table” of elements
f.
The periodic table shows all the elements
i.
ii.
iii.
iv.
v.
vi.
vii.
It lists elements and symbols, among other
things
Symbols are one, two, or three letters.
Single symbols are capitalized – ex H, N, O, F
Two letter ones: First capitalized, second
lowercase – ex He, Br, Li
Three letter ones: not a permanent name –
only first is caps – Uuh, Uuo
Some symbols come from the English name.
Some come from Greek or Latin names for the
elements.
You need to know the following ones:
1. Elements 1-88
II.
The Mole
a.
This unit is designed to bring the infinitesimally
small numbers associated with nuclear particles
and single atoms up to something we can work
with in the real world
A mole is defined as the fundamental SI unit
used to measure the amount of a substance, or a
collection of 6.022137 x 1023 particles.
It is abbreviated mol or n.
This number was chosen because there are
exactly that many particles of a substance in the
atomic mass of an element when it is expressed
in grams.
b.
c.
d.
i.
ii.
Example – There are 6.022137 x 1023 particles in 12.01
g of carbon
There are 6.022137 x 1023 particles in 35.45 g of
chlorine.
Molar Measurement
Virtual Lab 2 video
e. This number, 6.022137 x 1023 , is usually
rounded to 6.02 x 1023 , and is known as
Avogadro’s number.
f. Comparisons of a mole
i.
If 5 billion people were to count 1 atom per
second, they would need 4 million years to
count to 6.02 x 1023 atoms.
ii. If the surface of the United States was covered
by 1 cm3 cubes, the pile of cubes would be 50
miles deep.
iii. In comparison, 18 ml of water contains one
mole of water molecules.
Avagadro’s Number virtual
Lab 2 video
Questions:
1. What is an element?
2. Make a chart listing the three particles
that make up an atom, their locations,
charges, and masses.
3. What is a mole?