SCIENCE 90PHYSICAL SCIENCE

ATOMS AND ELEMENTS

CHEMISTRY UNIT OBJECTIVESPART A – PHYSICAL VS CHEMICAL PROPERTIES OF COMMON SUBSTANCES

1. Explore properties of matter, traditional uses of matter and physical and chemical properties of matter.

2. Investigate common materials and substances and classify them according to their physical and chemical properties.

3. Investigate changes in the properties of matter and identify indicators of chemical change.4. Explore chemistry related science that exists in Saskatchewan.

PART B – HISTORICAL EXPLANATION OF STRUCTURE OF MATTER5. Explore and describe atoms and elements (anatomy, molecules, compounds, charges, periodic table info.)6. Explore First Nations and Metis views on Matter.7. Identify the development of theories on matter and construct models to identify the major historical

atomic models (Bohr, Dalton, Thomson, Rutherford, Bohr)

PART C – CLASSIFICATION OF SUBSTANCES (PERIODIC TABLE)8. Differentiate between and be able to classify matter as either elements, compounds and mixtures.9. Identify common elements and compare structure, graphic representations and examples of

diatomic molecules. 10. Write and interpret chemical symbols and formulas in common compounds.

11. Trace the historical development of the periodic table and explore its organization (rows, columns,

families, metals, non-metals, etc…)12. Be able to determine atomic characteristics using information from the periodic table.

Objective 1: Matter and its Properties Hunting the Elements - NOVAWhat is “Matter”?

Anything in the universe which:1-has a MASS (made up of ATOMS =

basic building block of matter)2-has a VOLUME (takes up space)

Demo – Vacuum Jar

Which of the following can be considered matter?Light Air Steam EnergyMemories Soundwaves CO2

You Olive Oil Fire

Cell = basic building block of living things..jpg

Atom = basic or simplest building block of matter or stuff (living or non-living).http://www.wimp.com/seenatom/

Molecule = more than one atom attached together

Compound = more than one atom attached together (MUST CONTAIN DIFFERENT KINDS OF ATOMS)

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Molecule or Compound?

Phases of Matter:All matter exists in one of 4 phases as seen above:

-Energy and the Four States of Matter Solid Liquid Gas and Plasma - YouTube

The Particle Theory of Matter1. All matter is made up of small particles. (Particles can be atoms or molecules.)2. All particles of the same substance are identical.3. The particles of matter are attracted to one another. (Attractions are stronger if particles are closer together.)4. The spaces between the particles are large compared to the particles themselves.5. The particles of matter are in constant motion.

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When examining atoms and molecules we either explore the:

Physical Properties = characteristics of a substance which can be observed without changing the atomic makeup of the substance

(freezing point, color, smell, density, etc…)

Water - > Ice --> Steam Periodoc table showing temp for change of state

Chemical Properties = characteristics that describe a substance as it is atomically changed. (combustion temperature, reactivity with other chemicals, etc…)

Blue Paint + Yellow Paint = Green Paint

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Objective 2&3: Investigating Materials according to their Physical and Chemical Properties

and Examine Indicators of Physical Change

Demo activity handout on Physical properties through changesPotassium iodide and lead nitrate – YouTube

Quick science: Iodine clock reaction – YouTube

Microwave Ivory Soap - Cool Science Experiment - YouTube

http://www.wimp.com/glasstechnologies/

The Chemistry of Snowflakes on Devour.com

Chemical Change• In a chemical change, the

original substance is changed

into one or more different

substances that have different

properties.

• Chemical changes always involve the production of new substances.

• Chemical changes are difficult to reverse.

• Examples include burning, cooking and rusting.

How can you tell if a change is chemical or physical?

• There are many signs that can tell us. Consider several clues before coming to a conclusion.

1. A new color appears

2. Heat or light is given off

3. Bubbles of gas are formed

4. A solid material (called a precipitate) forms in a liquid.

5. The change is difficult to reverse.

COLOR

HEAT&LIGHT

BUBBLES

PRECIPITATE

Quiz - Chem or Phys Change?

Bleach on colored paperIodine on a starchy cracker

4 6.17.

Objective 4:

• Saskatchewan Chemist Jobs

• U of S Crop Chemist Breakthrough You tube

• Careers in Chemistry - Youtube

Objective 5: Atoms and Elements

ATOM = The basic building block of all

matter.

MATTER =Anything that has mass and

volume.

ELEMENT = any one kind of atom (helium,

oxygen, carbon, etc…)

= the periodic table is all of the

elements that we know of in

our universe

• Solving the puzzle of the periodic table. [VIDEO]

Anatomy of the Atom:• An atom is made up of a:

Nucleus = dense center where virtually all of the mass of the atom is found. It is made up of:

Protons (+charge)and Neutrons (0 charge)

- The nucleus is surrounded by orbiting Electrons (- charge)- Electrons in orbit make up most of the volume of the atom but have a mass of virtually nothing.Atom Animation - YouTube

• How small is an atom?

• How does an atomic accelerator Work?

Elements:

7

NNitrogen14.0067

Atomic # (Number of Protons and # of Electrons)

Atomic Symbol

Element Name

Atomic Mass

• Atomic # = # of Protons (and the # of electrons before an atom reacts)

• Atomic Mass = # of Protons + # of Neutrons (components of Nucleus)

• Mass = # Protons + # of Neutrons

______ = _____ + ______

interactive periodic table

Assignment: Please complete handout on “Element information”.

Build an Atom - Atomic Structure, Atoms, Atomic Nuclei

- PhET

Creation of Compounds: Why do Atoms Bond Together?• All elements have electrons orbiting around the

nucleus’s. There can be 1, 2 or many orbits and each orbit can hold a different amount of electrons.

• Chemical Reactions - Periodic Table of Videos - YouTube

1st Orbit = 2 electrons

2nd orbit = 8 electrons

3rd orbit = 8 electrons

4th orbit = 18 electrons

Each atom is trying to have a full

orbit of electrons!

• How Atoms Bond -

Chemical reactions result when two or more atoms come together in such a way as to fill their outer electron shells (valence shells).Reaction s can be one of two main types: Ionic bond

• In an ionic bond one atom has such a strong attraction for the electrons (electro-negativity) that it pulls an electron away from another atom. This results in the two atoms now having charge.

Covalent Bond• A covalent bond generally forms when two

atoms of the same element are bonded together Since the atoms have the same attraction for electrons (electronegativity) neither atom can completely remove an electron from the other and as a result they share the electrons equally.

• Ionic and covalent bonding animation - YouTube

Objective 6: First Nations P of V

• Please read the article and answer the following questions:

Objective 7: History of Atomic Model (Aristotle(360BC),

Dalton(1803), Thomson(1897), Rutherford(1911),Bohr(1922)

1 Aristotle (Greek era)

– Atom = uncuttable

-(smallest form of a

particle)

-4 elements made up

everything else

Dalton (1803)• Based theories on Experimentation• Came up with the atomic theory:

– 1. All elements are made up of invisible atoms.– 2. Atoms of the same element are identical.– 3. Atoms of different elements combine to form

compounds.– 4. Chemical reactions are the rearrangement of

atoms but atoms cannot be split. (This is the only part of his theories that has later been disproved!)

Thomson (1897)

• Provided 1st evidence that atoms are made of even smaller particles with charges.

• Made the Plum Pudding analogy

Rutherford’s Atomic Model

• Rutherford developed a new model for the atom.

• An atom has a tiny, dense positive core called the nucleus (which deflected the alpha particles and contains protons.)

• The nucleus is surrounded mostly by empty space, containing rapidly moving negative electrons (through which alpha particles pass unhindered.)

Atomic Models: Bohr• Niels Bohr proposed a

“planetary” model of the atom.

• Electrons are found in specific energy levels called orbits– Like planets around the

sun

• Each electron in an orbit has a definite amount of energy.

• The further the electron is from the nucleus, the more energy it has.

• Electrons do not exist between the orbits but can move from one orbit to another.

• The order of filling of electrons in the first three orbits is 2, 8, 8.

• Electrons are more stable when they are at lower energy, closer to the nucleus.

Bohr Diagrams• Bohr’s model was

readily accepted by scientists and they began drawing models of the atom using his theory.

Bohr-Rutherford Diagrams• This diagram is a combination of

Rutherford's nuclear model and Bohr’s planetary model.

• It summarizes all of the sub atomic particles in the atom

Structure of the Atom 1: The Earliest Models - YouTube

17 p+

18 n0

Chlorine

Scroedinger – Present Atomic Model

Based on wave mechanics and the probability of where electrons would be found about the nucleus.

HowStuffWorks "Assignment Discovery: Origin of the Atom Theory"

Objective 8: Elements, Compounds, and Mixtures

A Chemical reaction:

-Involves a transfer of electrons (Ionic)

OR a sharing of electrons (Molecular)

-Happens as elements try to fill an outer orbital (Valence electrons)

We can describe a molecule or compound based on how many atoms of each element it possesses.

2 forms of Gasoline

• When 2 or more elements react (Compound) a FORMULA is used to describe the reaction.

What is this?Nitrogen: 20-90%Hydrogen: 0-50% (flammable)Carbon dioxide: 10-30%Oxygen: 0-10%Methane: 0-10% (flammable)

Examples of Compounds

Examples of Formulas for compounds

Examples of names ofcommon compounds

H2O Water

C6H12O6 Glucose

C2H6O Alcohol

NaCl Salt

C2H6O Ethanol

C2H4O2 Vinegar

NH3 Ammonia

C2H4O2 Acetic Acid

C4H10 Butane

H2SO4 Sulfuric Acid

CH4 Methane

C12H22O11 Sucrose

C3H8 Propane

NaHCO3 Baking Soda

N2O Nitrogen

C6H8O7 Citric Acid

C8H18 Octane

C10H16O Camphor

Objective 9: Structure of Common ElementsPlanetary models of the first 18 elements assignment

Crossword on elements

Article on castle of elements

Objective 10: Chemical Symbols and Formulas in Compounds

• Chemicals React! – All elements want to become like the Noble gases (with a full outer orbital of electrons) and will react with other elements until they do.

• As a result electrons will be gained or lost.

• All chemical reactions must follow the basic law of “Conservation of Matter”.

Skill #1• Accounting for Atoms in a Molecule: • A formula is the correct combination of elements into an particular molecule.

It is very dependant on the correct listing of atoms and amounts of each.

What elements are in these molecules and how

many are there?

SULFURIC ACID H2SO4 =

SUGAR C6H12O6 =

CAFFEINE C8H10N4O2 =

Handout -

Rules for Writing a Chemical Formula:1. Lower case #’s (subscript) refer only to the element

immediately preceding the #.Eg. Na2 =

2. A lower case # (subscript) after a set of brackets refers to all the atoms within the brackets preceding the #.Mg(OH) 2 =

3. A large # in front of the atoms (“Coefficient”) refers to all the atoms following the # in that molecule.2NaCl =

4. When trying to determine the #’s of atoms, multiply the Coefficient in front by the lower case #’s behind of elements.2Ca(OH) 2 =

Handout Answers

1. 2 H, 2 Cl 13. 3 H, 1 P, 3 O

2. 2 H, 1 S, 4 O 14. 1 H, 1 P, 3 O

3. 2 Na, 6 Cl 15. 1 H, 1 C, 1 N

4. 6 Na, 12 O, 12 H 16. 2 H, 2 S, 7 O

5. 2 H, 2 S, 6 O 17. 3 Ag, 1 P, 4 O

6. 4 H, 2 C, 4 O 18. 1 Co, 3 Cl

7. 36 C, 72 H, 36 O 19. 1 Fe, 3 Mn, 12 O

8. 1 Na, 1 Cl 20. 2 N, 4 H, 2 O

9. 2 B, 2 S 21. 2 Al, 3 S

10. 4 Na, 8 Cl 22. 1 Zn, 2 I, 8 C

11. 1 As, 3 C, 3N 23. 1 Ni, 2 As, 6 O

12. Same as 23 24. 2 I, 7 O

13. 2 Ba, 1 Si 25. 1 Au, 1 N, 1 S, 3 O

Skill #2• Reaction Types: Describe a reaction as being

either:– Synthesis (smaller elements or molecules react to form larger ones)

- Decomposition (larger molecules get broken down into smaller ones)– Single Replacement (One element in a molecule gets traded for

some new element stepping in)– -Double Replacement (elements from 2 different molecules switch

partners)– Combustion (A compound rectas with Oxygen and the products have

some new molecule)

Eg. Burning of Methane:

1 CH4 + O2 ----} CO2 + 2 H2O

Skill #3 Balancing Equations• The Law of Conservation of Mass:

– 1 Matter cannot be created or destroyed.– 2 The total mass of all reactants before a

chemical reaction must be the same as

the total of all products after the chemical

change has taken place.

How to Balance a Reaction:

• 1. Adjust the numbers of each kind of atom by writing COEFFICIENTS in front of the formulas of the compounds and elements.

• 2. DO NOT use subscripts as this changes what the molecule is! Eg. (H2O ----} not H2O2 but 2H2O

Examples:

1. H2O ----} H2 + O2

2. Na + Cl2 ------} NaCl

3. Fe + H2O --------} Fe2O3 + H2

Objective 11: History and Organization of the Periodic Table• The Periodic Table: Crash Course Chemistry #4 - YouTube• The genius of Mendeleev's periodic table - Lou Serico – YouTube• Solving the puzzle of the periodic table - Eric Rosado - YouTube

• Please complete the following textbook reading: Pg177-188,190 Answer questions on pg 188 – (1,4,5,6,7) Pg 191 – (2,3,4)

Mendeleev’s table from 1869

Objective 12:

• Please complete the handout (Element Squares and Planetary Info.) as a review of Atomic Information found on the Periodic Table: