Turbo TAKS Week 4 Lesson 1: Matter Lesson 2: Density Lesson 3: Periodic Table Lesson 4: Chemical Formulas

1
Turbo TAKS
Week 4 Lesson 1 Matter Lesson
2 Density Lesson 3 Periodic Table
Lesson 4 Chemical Formulas
2

• All matter can be classified into one of three
  areas
• 1. Elements
• 2. Compounds
• 3. Mixtures
• Elements Elements are the basic chemical
  structures that cannot be broken down.
• Examples
• I- Iodine
• Na- Sodium
• Co- Cobalt
• C- Carbon

3

• Compounds are formed when two or more atoms
  chemically
• combine.
• They cannot be separated by physical means.
• Examples
• NaCl- Salt
• CO2- Carbon dioxide

4
Mixtures are formed when two or more substances
are mixed together but they are not
chemically combined. Mixtures can easily be
separated by physical means. (Distillation, using
a magnet, dissolving one in water then letting
the water evaporate.) Heterogeneous
Mixture Mixtures that are not the same
throughout. Examples Pizza, Salad If you take
multiple samples of it, they may look different
from each other! Homogeneous Mixture A mixture
that is the same throughout. Examples
Kool-Aid, Brass
5
Physical/Chemical Changes

• Physical Changes in matter that do not affect the
  chemical composition of the material. They often
  alter the volume, shape, or texture of the
  material, but it is often possible to undo a
  physical change and return the material to its
  former condition.
• Ex. Phase changes (melting, freezing,etc)
• It is the SAME SUBSTANCE.
• Chemical Changes in matter do ALTER
  the chemical
  
  composition of the material.
  You get a NEW SUBSTANCE.
• Ex. Producing a gas, heat change,
  color change
• Wood burns into ash and smoke.
  Stomach acid digests your food. Metals
  rust (oxidation).

6

• Lesson 2 Density, Viscosity, Buoyancy

7
DENSITY

• Density is the ratio of mass to volume and can be
  calculated by dividing the mass by the volume.
• Whether your sample is cut in half, quarters, or
  little bitsy pieces, the density REMAINS THE SAME
  throughout!
• Denser liquids will sink under less dense ones.
  
• Liquids mixed in a container will separate into a
  column of distinct layers.

D mass/volume Common units of density include
g/mL, g/cm3
8
Density

• Density of a substance changes as it goes from
  solid to liquid to gas.
• The only factor that affects density is
  temperature.

9
BUOYANCY the ability to float

• If you place an object in a liquid like water,
  the water will push upward with a buoyant force
  equal to the weight of the water displaced by the
  object.
• If the average weight of the object is less than
  the weight of the displaced water, the object
  will float. This buoyancy explains why ships that
  weigh thousands of tons are able to float on the
  ocean.
• If a material floats in water (buoyant) than its
  density is less than
• 1g/mL- if it sinks, its greater than 1 g/mL.

10
VISCOSITY

• A measure of how much fluid resists flowing.
• High density High viscosity
• Depends on temperature
• Viscosity decreases as temperature increases.
• Low viscosity water
• High viscosity syrup or oil

11
Lesson 3 Periodic Table
12
Atoms

• An atom is the smallest particle of an element
  that has all the properties of that element
• The three parts of an atom are
• Protons (positive)
• Neutrons (neutral)
• Electrons (negative)
• Protons/Neutrons are found in the nucleus while
  electrons are found in an electron cloud outside
  the nucleus.
• Valence electrons are in the outermost energy
  level and are responsible for bonding.

13
Atomic Structure

• Sodium-23 ? The 23 is the mass number
• Atomic number number of protons
• Mass number number of protons and neutrons in
  the nucleus

14
Groups and Periods

• Groups or families (vertical column) of elements
  are listed by increasing atomic number and they
  have similar chemical properties.
• Ex. calcium and magnesium would have similar
  properties.
• Horizontal rows are called periods.
• Group 1 Alkali Metals are the most reactive
  metals
• Group 17 Halogens are the most reactive
  nonmetals. These two groups are most likely to
  form bonds together.
• Group 18 Noble Gases are resistant to
  bonding and largely nonreactive. This is
  because they have 8 valence electrons making them
  stable atoms.

15
Metals and Nonmetals

• Properties of Metals
• Metals are electron LOSERS.
• Located on the left side of the stair step
• Bright, metallic luster
• Conduct heat and electricity
• Malleable and ductile

• Properties of Nonmetals
• Nonmetals are electron LOVERS (Gain/ Take
  electrons in chemical reactions)
• Poor conductors of heat and electricity
• Usually brittle
• Lower melting points
• Many are gases at room temperature

16
Lesson 4 Chemical Formulas

• How do you write a chemical formula?
• Write the symbols and oxidation numbers for each
  ion. Write the ion with the positive charge on
  the left
• Pb4 O-2
• Criss-Cross the charges by writing each charge as
  the subscript for the other. Ignore the signs.
  
• Pb4 O-2 Pb2O4
• Simplify the ratio. Do not write the subscript 1
  
• PbO2

17
Polyatomic Ions

• A special class of ions where atoms are
  covalently bonded together

18
Short list of polyatomic ions