Ch 1 Homework: due Monday 4 pm

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Ch 1 Homework due Monday 4 pm Ch 2 Homework
due Friday 4 pm 2.2, 2.6, 2.10, 2.14, 2.16,
2.20, 2.38, 2.44, 2.46, 2.48, 2.52, 2.54 Typo on
problem 2.20 (copper has 34 neutrons, not 63)
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Classification of Matter
Matter Has mass and takes up volume
Pure Substance A single component
Mixture More than one component
Element Contains only one type of atom
Compound Composed of two or more chemically
combined elements
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Classification of Matter
Element, compound, or mixture?

• Blood

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Classification of Matter
Element, compound, or mixture?

• Blood Mixture (red blood cells, plasma, other)
• Water

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Classification of Matter
Element, compound, or mixture?

• Blood Mixture (red blood cells, plasma, other)
• Water Compound (H2O)
• Radon

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Classification of Matter
Element, compound, or mixture?

• Blood Mixture (red blood cells, plasma, other)
• Water Compound (H2O)
• Radon Element (Rn, see periodic table)
• Aluminum foil

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Classification of Matter
Element, compound, or mixture?

• Blood Mixture (red blood cells, plasma, other)
• Water Compound (H2O)
• Radon Element (Rn, see periodic table)
• Aluminum foil Element (Al, see periodic table)
• Saline

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Classification of Matter
Element, compound, or mixture?

• Blood Mixture (red blood cells, plasma, other)
• Water Compound (H2O)
• Radon Element (Rn, see periodic table)
• Aluminum foil Element (Al, see periodic table)
• Saline Mixture (NaCl in H2O)
• Diamond

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Classification of Matter
Element, compound, or mixture?

• Blood Mixture (red blood cells, plasma, other)
• Water Compound (H2O)
• Radon Element (Rn, see periodic table)
• Aluminum foil Element (Al, see periodic table)
• Saline Mixture (NaCl in H2O)
• Diamond Element (C)

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Matter Can Undergo Physical and Chemical Changes
Physical change A change a substance undergoes
where it remains the same chemical
composition Chemical change A change a
substance undergoes where it becomes a new
substance with different chemical composition
Is the sublimation of dry ice (solid CO2) a
physical or chemical change?
Is the digestion of carbohydrates such as
lactose a physical or chemical change?
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Matter is Composed of Atoms

• An atom is the smallest unit of a chemical
  element.
• Compounds are composed of elements.
• Mixtures contain compounds and/or elements.
• Matter includes elements, compounds, and
  mixtures and thus all matter is composed of
  atoms

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Atoms are Composed of Sub-Atomic Particles
Protons Positive charge 1 amu
Neutrons No charge (neutral) 1 amu
Electrons Negative charge 0.0005 amu
Subatomic particles
(1 amu 1.67 x 10-24 g)
Electrons form a cloud surrounding the
nucleus Majority of atomic size
Protons and neutrons are in the nucleus Majority
of atomic mass
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Atoms are Composed of Sub-Atomic Particles
Cartoon does not accurately depict the modern
view of an atom
Protons Positive charge 1 amu
Neutrons No charge (neutral) 1 amu
Electrons Negative charge 0.0005 amu
Subatomic particles
(1 amu 1.67 x 10-24 g)
Electrons form a cloud surrounding the
nucleus Majority of atomic size
Protons and neutrons are in the nucleus Majority
of atomic mass
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Electron Cloud Model of An Atom
1 femtometer (fm) 10-15 m
1 Ångström (Å) 10-10 m
Electron cloud is 100,000 times larger than the
nucleus
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Electron Cloud Determines Atomic Size
If the atomic nucleus were the size of a
marble, a typical atom would be the size of a
football field
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Classification of Matter
Matter Has mass and takes up volume
Pure Substance A single component
Mixture More than one component
Element Contains only one type of atom
Compound Composed of two or more chemically
combined elements
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Elements Contain Only One Type of Atom
Each element is assigned a name and an atomic
symbol Oxygen O Carbon C Hydrogen H Nitrogen
N Calcium Ca Phosphorous P Chlorine Cl Potassiu
m K Sulfur S Sodium Na Magnesium Mg
What is significant about these elements?
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Elements
Each element is defined by the number of protons
in its nucleus atomic number The total number
of protons and neutrons in an atom mass
number Atomic notation includes atomic symbol,
mass number and atomic number 12
mass number 6 atomic
number C atomic symbol
Atomic notation may be written without the atomic
number 12C
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Isotopes
Isotopes are atoms of an element that have a
different number of neutrons
carbon-12
carbon-13
carbon-14
How many protons does carbon-12 have?
Carbon-13? Carbon-14? What is the atomic number
of carbon-14? What is the mass number of
carbon-13? How many neutrons does carbon-12
have?
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Periodic Table of the Elements
Includes atomic symbol, atomic number, atomic
weight
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Periodic Table of the Elements

Period 1
Period 2
Period 3
Period 4
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Periodic Table of the Elements

Group 8A Noble gases
Group 1A Alkali metals
Group 7A Halogens
Group 2A Alkaline earth metals
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Periodic Table of the Elements

Metals
Non-metals
Semi-metals
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The Mole and the Periodic Table
The atomic weights of the elements are listed on
the periodic table in g/mol. Hydrogen weighs
1.0080 g/mol
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What is a Mole?
1 dozen 12 1 bakers dozen 13 1 quartet
4 1 mole 6.02 x 1023
Counting units
Why is the mole so large? In real life we deal
with such a huge number of atoms that we refer to
them in terms of moles, or units of 6.02 x
1023. Where did 6.02 x 1023 come from? A mole
of carbon-12 weighs exactly 12 g (assigned
definition), so a mole is the number of atoms in
12 g of carbon-11.
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The Mole and the Periodic Table
If carbon-12 is defined as weighing 12 g/mol,
why does the periodic table indicate 12.0107
g/mol? Carbon exists as carbon-12, carbon-13,
and carbon-14. 12.0107 is the weighted average
of the naturally occurring isotopes. The most
abundant carbon isotope is carbon-12 (atomic
weight of C 12.0107 g/mol).
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Atomic Weight and Molar Mass
Mass of a proton 1 amu Mass of a neutron 1
amu Mass of an electron 1/2000 amu
(negligible) Atomic weight of carbon
12.0107 amu Molar mass of carbon 12.0107
g/mol 1 mole 6.02 x 1023 We will typically
speak in terms of g/mol
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Problems

• Give the atomic symbol for sodium, potassium and
  chlorine
• Give the name of each element Ca, P, H
• How many protons, neutrons, an electrons are
  present in the neutral atoms
• The element hydrogen exists as three isotopes
  hydrogen-1, hydrogen-2, and hydrogen-3. Which is
  the predominant isotope found in nature?
• Complete the following for oxygen-16
• atomic symbol
• number of protons
• number of neutrons
• atomic number
• mass number

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Problems

• What is the atomic number and atomic mass of
• What is the atomic symbol and atomic mass of
• 3) Which of the two atoms is the more metallic?
  Mg or F
• 4) Name an element that is a halogen.
• 5) Name an alkaline earth metal.
• 6) How many atoms are contained in 1.0 mole of
  F?
• What is the atomic weight of Na?
• How many moles are contained in 5.0 g of Na?
• How many atoms are contained in 5.0 g of Na?