V-25: You Light Up My Life Classifying Substances of atom is bonded together. Example: Na, Cu, Cl 2 • Compounds are substances in which two or more types of atoms are bonded together

1. If you were to drop a spoonful of salt, NaCl, into a glass of water, what would happen?

2. If you were to drop a gold ring into a glass of water, what would happen?

3. What do you think is different about the atoms of these two substances? Why do you suppose the gold atoms don’t break apart?

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V-25: You Light Up My LifeClassifying Substances

ChemCatalyst

Work in groups of 3 to 4.

Wear safety goggles at all times during the lab.

Dissolve: To disperse evenly into another substance. For example, a solid can dissolve in a liquid.Conductivity: A property that describes how well a substance transmits electricity.


DEMO: Dissolving and conductivity can be demonstrated with a powdered sports drink and a light bulb assembly like the one shown below.


Generalizations about substances that do not light up the bulb:

Compounds made up of C, H, and O atoms do not conduct electricity.

Compounds made up entirely of nonmetals do not light up the bulb.

Compounds made up of a combination of metals and nonmetals do not light up the bulb when they are in their solid form.


Generalizations about substances that do light up the bulb:

Everything that lights up the bulb has a metal atom in it.Compounds made of metal and nonmetal atoms, such as salts, light up the bulb when they are dissolved in water. Metal solids light up the bulb.


Solubility and Conductivity


Soluble: can be dissolved; Insoluble: cannot be dissolved

Predict whether MgSO4(aq), commonly known as Epsom salts, will conduct electricity. State your reasoning.


Check-In

Wrap Up

How can substances be sorted into general categories?Not all substances dissolve in water.Not all substances conduct electricity.Solid metals and metal–nonmetal compounds dissolved in water conduct electricity.

Add this diagram to your notes; fill in blanks, use V-25 lesson to help

V-25: You Light Up My LifeReview

Soluble: can be dissolved; Insoluble: cannot be dissolved

A gold ring is made of individual gold atoms.

1. What keeps the atoms together so they just don’t fall apart?

2. What parts of the atom do you think are responsible for keeping the atoms together in a solid?

V-26: Electron GlueBondingChem Catalyst

Chemical Bond: An attraction between atoms that holds them together in space.

How are atoms connected to one another?

V-26: Electron GlueBonding

Four Models of Bonding


Metal atoms Non-Metal atoms Metal & Non-Metal atoms

Metallic Covalent Network Molecular Covalent Ionic


Bonding also relates to the type of atom in the substance—metal or nonmetal.

Four Models of Bonding


Au – gold

Cu – copper

Al – aluminum

SiO2 – sand

C20H42 - paraffin

H2O – water

C12H22O11 – sugar

C2H6O - ethanol

NaCl – salt

CaCl2 – calcium chloride

CuSO4 – copper sulfate

• Elements are substances in which only one type of atom is bonded together.

Example: Na, Cu, Cl2

• Compounds are substances in which two or more types of atoms are bonded together.

Example: NaCl, H2O, CuSO4



Wrap-Up

• A chemical bond is an attraction between atoms involving the valence electrons.

• There are 4 types of bonds: ionic, covalent network, molecular covalent, and metallic.

• Valence electrons are distributed in different ways between atoms depending on the type of bond.



Wrap-Up

Discussion Notes (cont.)

The chart created in the previous lesson can now be labeled with the four types of bonds.

Wrap Up

How are atoms connected to one another?A chemical bond is an attraction between atoms involving valence electrons.There are four types of bonds: ionic, network covalent, molecular covalent, and metallic.Valence electrons are distributed differently depending on the type of bond.

Identify the type of bonding present in each group below: ionic bonding, molecular covalent, network covalent, or metallic bonding.


Review (add to notes)

1. 2. 3. 4.

1. What is the charge on the copper ions in this copper chloride compound?

2. How do you think we could get solid copper from a sample of copper (II) sulfate, CuSO4?

Copper and chlorine atoms combine to form copper (II) chloride.

V-27: Electrons on the MoveElectroplating Metals

Chem Catalyst

Can we get an element from a compound?

Electroplating: Using electricity to transform metal ions into neutral metal atoms

CuSO4 (aq)Cu(s)


Lab Prep

Work in pairs. Wear safety goggles at all times.

The solution contains acid, which is corrosive. Before handling the nickel strip, rinse it with water.


Lab Prep

Electroplating: Using electricity to transform metal ions into neutral metal atoms

Nickel Strips – electrodes; allow electricity in and out of the solutiom

Aqueous copper (II) sulfate, CuSO4(aq), is really copper cations, Cu2+, and sulfate anions, SO4

2–.

Before connecting to the battery


Notes

It is possible to transform metal cations in solution into neutral metal atoms, using electricity.

Once the battery is hooked up, one nickel strip has a positive charge, and the other has a negative charge.

After connecting to the battery


Notes

Many elements are found in nature only in combination with other atoms in compounds.

While you cannot make gold by moving electrons, you can plate thin layers of gold onto jewelry.


Notes

Properties: The properties of elements include color, hardness, and reactivity.Also solubility (whether it dissolves), and conductivity.

CuSO4 (aq) Cu(s)


Notes

1. What is required to transform CuCl2(aq) into Cu(s)?

2. What is required to transform CuCl2(aq) into Au(s)?


Check-In

Documents

V-25: You Light Up My Life Classifying Substances of atom is bonded together. Example: Na, Cu, Cl 2 • Compounds are substances in which two or more types of atoms are bonded together