Chapter 5 Study Guide

Chapter 5 Study Guide

Chemical Bonding

Review Notes, Labs, Homework, and the Textbook.

1.    Using the Periodic Table, you should be able to draw the electron dot diagram for all of the elements covered in class.

2.    Ionic Bonds

A.    Know that an ion is a charged atom or group of atoms

B.    A polyatomic ion is what we call a charged group of atoms

C.    Atoms become charged when the gain or lose electrons.

D.   Atoms have positive charges when the lose electrons (mostly metals) and negative charges when they gain electrons (mostly nonmetals).

E.    Ionic Bonds form when electrons are transferred from one atom to another resulting in ions.  The opposite charges of the ions attract each other.  This is a very strong bond.

F.    You should know how to write chemical formulas using ion charges.  You should know how to name compounds using the chemical formula.  I will give you an ion list to use on the test.

G.    You should know the characteristics of ionic compounds:

1)   Ionic compounds form crystals because of the regular repeating pattern of ions.

2)   Conduct electricity when dissolved in water.

3)   High melting points

4)   Not flammable

5)   Almost all ionic compounds (salts) are formed from

a metal and a nonmetal bonding.

3.    Covalent Bonds

A.    Know that covalent bonds form when atoms share electrons.

B.    Usually form when nonmetals bond to other nonmetals.

C.    Sometimes atoms have to share lots of electrons when they bond (example: Nitrogen forms a triple bond).

D.   Covalent molecules often have low melting points and burn easily (more flammable).

E.    Most covalent compounds do not conduct electricity in water like ionic compounds do.

F.    If electrons are not shared equally between all atoms, the molecule is said to be polar.  A polar bond makes one part of the molecule more positive and another part of the molecule more negative.  An example is water where the Hydrogen atoms are more positive and the oxygen is more negative because the electrons like the oxygen better.

Chapter 4 Study Guide

Chapter 4 Study Guide  - The Periodic Table and

The Structure of the Atom

I.              Students will need to be able to identify the groups of the periodic table and their characteristics.

A.   Metals and Nonmetals

B.  Alkali Metals

C.  Alkaline Earth Metals

D.  Transition Metals

E.   Metalloids / Semi-metals

F.   Halogens

G.  Noble Gases

H.  Radioactive and Synthetic Elements

II.            Students will need to be able to find the number of protons, neutrons, and electrons for an atom of an element using the periodic table.

III.          Students will need to know the structure of the atom and the characteristics of protons, neutrons, and electrons.

IV.          Know the definition of elements and atoms.

Know who Dmitri Mendeleev was

Chapter 3 Study Guide

Chapter 3 Study Guide

Chemistry – Properties of Matter

Solids, Liquids, and Gases

Study all Labs, Homework Sheets, Handouts, Graphic Organizers, and Notes.  You may also refer to Chapter 3 in your book.

Know definitions for the following terms:

Supercooled water       Amorphous solid      Crystalline Solid    Solid

Fluid                            Gas                            Liquid                   Surface Tension        Temperature               Thermal Energy        Viscosity                Evaporation

Vaporization                Boiling

Know the definitions, molecular movement, and processes involved for each of the following:  (Example:  Melting – Solid to Liquid – Increase in Molecular Motion)

Melting                 Evaporation         Sublimation            Freezing

Condensation       Resublimation

Know that TEMPERATURE and PRESSURE are two factors that can affect the phase of matter.

Be able to explain the Gas Laws and give examples of each (Charles’s Law, Boyle’s Law, and Temperature/Pressure)

Know the effects of changing temperature, pressure, and volume of a gas.

Know that water freezes at 0 degrees C and boils at 100 degrees C.

Know your labs – why we did the labs and what they showed. Labs to know:  Freezing point lab, Marshmallow Madness Lab, Endothermic and Exothermic Lab, and all gas demos.

FROM CHAPTER 2 KNOW THE FOLLOWING:

Be able to define, describe, and identify chemical changes, physical changes, endothermic reactions and changes, and exothermic reactions and changes.

Know that electricity can be used to break molecules apart.  This is called electrolysis.  We used electrolysis to break bonds in water.  We saw gas bubbles produced and acids and bases produced.  That was the evidence that new substances had been formed – a chemical change.

Density and Buoyancy Study Guide

Study Guide

Density and Buoyancy

I.               Density

A.     Density is the amount of matter in a given space.  The formula for density is:  Density = mass/volume. 

B.     Students should know how to solve density problems.

C.     Students should know the definitions and units for mass and volume.

D.    Know that density is a property of matter - no matter how much you have of a pure substance, the density remains the same.

E.     Know that the density of water is 1 g/mL (1 g/cm³).  And that objects with a density less than 1.0 g/mL will float and objects with a density greater than 1.0 g/mL will sink.

II.             Buoyancy

A.     Buoyancy is an upward force exerted by a fluid (a fluid is substance that flows – a liquid or a gas).  It is always an UPWARD force.

B.     Archimedes’ Principle states that for a floating object, the weight of the object equals the weight of the water displaced.

C.     Be able to explain, using buoyancy, why some objects float (like a heavy aircraft carrier) and some objects sink.

D.    If buoyant force is less than the weight of the object, the object will sink.  If buoyant force is the same as the weight of the object, the object will float.  (Buoyant force can’t be greater than the weight of the object because then the object would fly out of the water!)

E.     Buoyant force is a force and is measured in Newtons like weight.

(kg x meters /seconds² = Newton)

Chapter 2 Study Guide

      Chapter 2 Test Study Guide

Properties of Matter

To study for this test please use your brown notes on the Properties of Matter and Exothermic/Endothermic Reactions vs. Changes.  Also use labs on Recrystallization of Salt, Chemical Changes, Endothermic and Exothermic reactions (Hot or Not?), and the Electrolysis lab.  Use homework assignments and the graphic organizer on physical and chemical changes and your textbook pages 58 – 77 as well.

Vocabulary to Know:

Energy   Matter    Properties of Matter     Physical Properties

Chemical Properties    Element     Atom      Molecule    Compound  

Mixture      Homogeneous Mixture     Heterogeneous Mixture

Solution      Physical Change        Chemical Change    

Law Of Conservation of Matter        Thermal Energy

Temperature       Endothermic Reaction      Exothermic Reaction

Chemical Energy           Electrical Energy

Indicators of a Chemical Change         Precipitate

Concepts to Know:

1.    Everything is either energy or matter.

2.    Properties of matter are characteristics of a substance that help to identify that substance.  Physical properties are characteristics that can be observed and measured without breaking bonds or changing the substance chemically.  

Examples:  Color, shape, density, boiling point

Chemical properties can only be observed when a substance is changes chemically.

Examples: Reactivity with other chemicals, flammability

3.    An element is a pure substance that cannot be broken down into any other substance.  There are 92 naturally occurring elements in the universe.  Elements are organized on the Periodic Table of the Elements. 

4.    Atoms are the smallest particle of an element.

5.    Compound/Molecule – Two or more atoms chemically bonded.  Examples:  NaCl, CaCl₂, O₂, H₂O

6.    A mixture is two or more things together that have not been chemically bonded.  Solutions are a type of mixture where one thing dissolves into another. Examples: trail mix, salt water

7.    Heterogeneous Mixture – You can see the parts of the mixture

8.    Homogeneous Mixture – You can’t see the parts of the mixture.

9.    A physical change is a change in a substance that does not alter a substance chemically.  It’s still the same substance.

10.                  A chemical change is a change where bonds are broken and new substances are formed.  Example: Burning wood, reacting Sulfuric Acid and Sugar.

11.                  Law of Conservation of Matter says that whatever matter goes into a chemical reaction has to come out.

12.                  Thermal Energy is the measure of the amount of movement of molecules in a substance.  The more movement, the more thermal energy, the higher the temperature.  Temperature is a measure of the thermal energy of an object.  We measure thermal energy (temperature) with a thermometer.

13.                  Chemical Energy is energy stored in chemical bonds.

14.                  Electrical Energy is the flow of electrons from one place to another.  Electrical Energy can be used to cause a chemical change with a process called Electrolysis.

15.                  Know the indicators of a chemical change and that a precipitate is a solid formed from a chemical reaction between two or more substances.

Chapter 1 Study Guide

Quiz 8^th Grade Science  -   Friday September 7

1.    Know the steps of the Scientific Method

2.    Know what makes a “fair” test using the Scientific Method and what indicates a flawed experiment.

3.    Know the difference between Qualitative and Quantitative data.

4.    Know how to measure metric length, volume, and mass.  Know the units and the equipment needed to measure and calculate each.

5.    Be able to calculate metric volume using water displacement method and length x width x height.

6.    Be able to convert metric units using a metric “number line.”

7.    Know the difference between mass and weight.