Atom Molecule Compound - West Linn · 2013. 7. 16. · When an atom gains electrons it becomes more negatively charged, called an anion. When an atom loses electrons it becomes more

Monday February 11, 2013

Daily Goals

I can identify and explain the difference between an atom, molecule, compound, and ion.

I can identify the difference between a cation and anion.

I can identify if an atom will likely participate in ionic or covalent bonding by the number

of valence electrons.

I can identify and explain the difference between an organic and inorganic molecule.

Notes: I can identify and explain the difference between an atom, molecule and compound.

Definition Example

Atom

Molecule

Compound

Notes: I can identify and explain the difference between an atom and an ion.

Definition Example

Atom

Cation

Anion

Label each of the following as an atom (A), molecule (M) and Compound (C).

Identify each as being a neutral atom, cation, or anion:

C O Na+1

H+ Fe+2

Cl-1

I-1

N K+1

Counting Atoms Worksheet

Directions for each problem

1) write down the different elements in each compound.

2) write down how many of that particular atom there are

3) how many atoms are there total in the compound.

Examples:

1) NaOH Na - 1

O - 1 3 total

H - 1

2) 5 ZnSO4 Zn – 1 x 5 = 5

S – 1 x 5 = 5 30 total

O – 4 x 5 = 20

3) 3 Cu2(SO4)2 Cu- 2 x 3 = 6

S – 1 x 2 x 3 = 6 36 total

O – 4 x 2 x 3 = 24

1) NaOH 6) 4 HNO3 11) 4 Mg(OH)2

2) MgCl2 7) 4 Li2O 12) 2 NaOH

3) Li2SO4 8) 3 H2O 13) 4 Al2(SO3)3

4) NaC2H3O2 9) 3 Al2O3 14) 2 (NH4)3PO4

5) NH4Cl 10) 5 ZnSO4

I can identify if an atom will likely participate in ionic or covalent bonding by the number

of valence electrons.

Bonding

An atom will not react with other atoms when it outermost electron

shell is completely full. Such an atom is described as being inert. An

atom will react with other atoms when its outermost electron shell is

only partially full. Such an atom is described as being reactive. Atoms

that have an almost empty outermost electron shell, as well as atoms

that have an almost full electron shell can become stable by losing

electrons or gaining electrons. When this happens the balance

between protons and electrons are unbalanced—and the atom

becomes charged. When an atom gains electrons it becomes more

negatively charged, called an anion. When an atom loses electrons it

becomes more positively charged, called a cation. When two ions are

held together by a bond it is called an ionic bond.

When an atom has a partially full electron shell it can become stable

by sharing electrons with another atom. Like two children tugging to

gain possession of a teddy bear, electrons in covalent bonds are pulled

in opposing directions by the nuclei of the atoms involved. If the

children are of equal strength—the teddy bear will remain stretched

between them—this is the definition of a non-polar covalent

bond—equal sharing of electrons between two atoms.

In many molecules that form covalent bonds, one nucleus has a larger

positive charge than the other and therefore attracts electrons more

strongly. Just as a stronger child will be able to pull the teddy bear

closer to himself, so the electrons will spend more time near the

larger, more positive nucleus and less time near the smaller nucleus.

The larger atom thus takes on slight negative charge from the

proximity of the electron and the smaller atom acquires a slight

positive charge. This is a situation of a polar covalent bond.

Inert:

Reactive:

Charged Atom:

Anion:

Cation:

Ionic Bond

Non-Polar Covalent Bond:

Polar Covalent Bond:

Bonding:

Typically but not always….atoms that have 1, 2, 6 or 7 electrons in their valence shell will likely participate

in an ionic bond.

Typically but not always…atoms that have 3, 4, or 5 electrons in their valence shell will likely

participate in a covalent bond.

To Determine the Exact Bond using Electronegativity

If there is an electronegativity difference between the two atoms of:

Strength of Bond outside of water:

≥ 2 Ionic Bond (Strong Bond)

≥ .5 to < 2 Polar Covalent (Medium Bond)

0- < .5 Non-Polar Covalent (Weak Bond)

Determining Ionic Bonds Using Valence Electrons:

Complete the Table:

Determine the number of each atom that will be needed to create an stable ionic bond. Then write

the formula for each compound produced:

Determining Covalent Bonds Using Valence Electrons:

Complete the Table:

Notes: I can identify and explain the difference between an organic and inorganic molecule.

Definition Example

Inorganic

Organic

Tuesday February 12, 2013

I can explain what the activation energy is in a chemical reaction.

I can identify and explain the difference between an endothermic and exothermic

chemical reaction.

I can identify and label the activation energy diagram for an endothermic and exothermic

reaction.

Notes: I can explain what the activation energy is in a chemical reaction.

Definition Example

Activation

Energy

Heat of Reaction

Reactants

Products

Endothermic

Exothermic

1 Exothermic and endothermic reactions

Decide whether each of these reactions is exothermic or endothermic:

a) When two chemicals mix their temperature rises: _______________

b) A solid burns brightly and releases heat, light and sound: _______________

c) When two chemicals are mixed their temperature drops: _______________

d) Two chemicals will only react if you heat them continually: _______________

e) Plants take in light energy for photosynthesis: _______________

2 Making and breaking bonds

During chemical reactions the bonds between atoms break and new bonds form.

Energy must be absorbed to break a bond, so breaking bonds is endothermic.

Making new bonds is exothermic because energy is released.

a) When green copper carbonate decomposes, the equation is:

CuCO3 CuO CO2

copper carbonate copper oxide carbon dioxide

Is the reaction exothermic or endothermic? Use ideas about bonds to explain why.

products

reactants

ene

rgy

course of the reaction

3 ‘Make or break’

b) Most reactions involve bond breaking and bond making. This equation shows what happens when methane (CH4) burns in oxygen (O2). Mark the bonds broken in blue and the bonds formed in red.

c) Complete the table to show the number of bonds broken and formed:

Bonds broken Number Bonds formed Number

between carbon and hydrogen

between carbon and oxygen

between oxygen atoms

between hydrogen and oxygen

d) Is the reaction exothermic or endothermic overall?

________________________________________________________________________

e) The overall energy change is decided by the strength of the bonds that are broken or formed during the reaction. The stronger the bond the larger the energy change. Which bonds must be stronger in this reaction – the bonds broken or the new bonds formed?

________________________________________________________________________

f) An energy level diagram shows the energy taken in and released during the reaction. Add the reactants, products and their separated atoms to the correct places on the diagram.

Is the above reaction exothermic or endothermic? How much energy is in the reactants? How much energy is in the products? How much energy does it take for the reaction to take place? How much energy is stored or released during this reaction?

Is the above reaction exothermic or endothermic? How much energy is in the reactants? How much energy is in the products? How much energy does it take for the reaction to take place? How much energy is stored or released during this reaction?

Thursday February 14, 2013

I can explain what entropy is and how synthesis and decomposition reactions can

increase or decrease entropy.

I can analyze an activation energy diagram for endothermic, exothermic, synthesis,

decomposition and entropy.

I can count the number of atoms and bonds in a molecule or compound to determine if

entropy is increasing or decreasing.

Definition Example

Entropy

Synthesis Rxn

Decomposition

Rxn

For each of the following examples, determine if entropy is increasing or decreasing:

1. Hot water is moving towards cold water.

2. Separating jelly beans by color.

3. Not taking a bath for a week.

4. Not mowing your lawn.

5. Getting a hair cut.

6. Mixing ingredients to make cookies.

7. Majority of backpacks Rebecca sees on a daily basis.

8. A landfill.

9. Chiseling a sculpture

10. Putting herbicide on a weed.

11. Not watering your lawn.

12. Helping a hoarder clean their house.

Create an activation energy diagram to show the chemical reaction between glucose (C6H12O6)

and oxygen (O2) to create carbon dioxide (CO2) and water (H2O).

1. Determine if it is exothermic or endothermic reaction.

2. Determine if it a synthesis or decomposition reaction.

3. Show the reactants of the equation. Show the productions of the equation.

4. Show the number of atoms and bonds in the sugar, oxygen, carbon dioxide and water.

5. Indicate where entropy is decreasing or increasing.

Friday February 15, 2013

I can identify and explain the difference between a covalent and ionic bond.

I can identify the difference between a non-polar and polar-covalent bond

I can identify the difference between a intermolecular and intramolecular bond.

'

Does it pass both vertical and horizontal symmetry test?

Notes: I can identify the difference between a intermolecular and intramolecular bond.

Definition Example

Intermolecular

Bond

Intramolecular

Bond

Hydrogen

Bond