Unit 2: Chemistry 5.1: Matter What is Matter? What is Chemistry? Particle Theory of Matter 1. All matter is made up of _______________________________ that have ___________________ _______________________ 2. All particles of one substance are __________________. Different substances are made of ___________________________________________________ 3. Particles are in ______________________________________________ 4. The particles of a substance _______________________________________________________ 5. Particles __________________________________ States of Matter Changes of State Classification of Matter 5.2 & 5.3: Physical and Chemical Properties What is a Property? Physical Properties Two Types of Physical Properties: Examples of Physical Properties Property Definition Example Water is a at room temperature Sugar is composed of Four is a Aluminum foil has a A rusty nail has a Glass is Sand is The windows in the classroom are Frosted glass is The wall is Glass is Silly Putty is Property Definition Example Honey is Water is Wax is Diamonds are Aluminum is Glass is Copper is Copper wires have Plastics do not Iron has a Aluminum has a Sugar is Sand is Sugar is Water is Sulfur smells like Other examples: Chemical Properties Examples of Chemical Properties Property Definition Example Gasoline is Candle wax is Magnesium reacts with acid, producing gas bubbles and heat Mercury is 5.2 & 5.3 Physical and Chemical Changes PHYSICAL CHANGE ___________________ substance is formed The particles of the starting substance(s) _________________________________ The change can usually be _________________________________ Common Clues and Examples of a Physical Change: Clue Example CHEMICAL CHANGE at least one ___________________________ is formed The particles in the substance(s) _____________________ Is usually _________________________________________________ Evidence for a Chemical Change: 1. Formation of _________________________ NOT caused by ____________________ The _________ is the new substance 2. Changes in _______________________________________ Could get ________________ or __________________ _______________ is often an indication that heat is produced 3. Formation of a ______________________________________ A ________________ is formed when two _____________________________ are mixed 4. Distinct _________________________ eg. Adding blue food colouring to water is NOT a chemical change – blue was the colour of one of the original substances (this is just __________________________) 5. Distinct _____________________________ 5.6: Characteristic Physical Properties Characteristic Physical Properties A physical property that is ________________ to a substance and that can be used to ______________ the substance. For example, knowing the __________________________________ of a substance is not helpful, because these values aren’t _______________ to substances. 1. Freezing/Melting Point and Boiling Point Different substances ________________ and _____________________ at different temperatures. For example, water freezes/melts at ________ and boils at ________ But, mercury melts at ________ and boils at ________ Question: How does salt melt snow and ice? Why do we put it on our roads and walkways in the winter? Answer! Once salt is added to water, Adding salt_________________________________________, so it will __________ at a ________ temperature than pure water. Water with salt can stay a liquid until the temperature is as low as ___________ By adding salt to roads, 2. Density A measure of _________________________________________________________________, or how ___________________________ the particles are Calculated by dividing ________ of a substance by its ____________ Units are __________ (solid) or __________ (liquid) Example: a puffy marshmallow has the _________ mass as a squished marshmallow, but a __________ density (the squished mallow takes up less volume and its particles are closer together) Density Calculations Formula: Formula Triangle: Density Examples - Use the GRASS method G– (write value(s) given with symbol and units) R– (write symbol of what you are solving for) A– (write formula you will use) S– (sub in values to formula and solve) S– (write a statement that includes your final answer with UNITS!) 1. A softball has the mass of 360 g and a volume of 270 cm3. Find its density. 2. What is the mass of a silver coin which has a density of 10.0 g/cm3 and a volume of 4.0 cm3? 6.1: Introduction to The Periodic Table of the Elements What is an Element? What is a Compound? What is the Periodic Table? The Periodic Table is like a chemist’s ______________________. The alphabet is composed of 26 letters, but these 26 letters can make up countless words. The Periodic Table is a list of ________________ that can make up countless _______________, in many different combinations. “periodic” means “____________________________” Some Basic Information about the Periodic Table Element Symbol an abbreviation for an element seen on the periodic table Rules/Patterns for Element Symbols: 1. Composed of either ________________________________ 2. The first letter is always ____________________. The second letter is always ______________ 3. Usually contains letters from the ________________________ C= Ca = Cl = 4. Some symbols are based on the ___________________. Ag stands for ___________ because its Latin name is __________________ Groups and Periods Horizontal rows are called ___________________ Vertical columns are called __________________________________________ Which element is in: Group 4, period 5? Group 1, period 6? Group 18, period 2? Metals and Non-Metals The _________________________ divides the ______________________________________ Metals are found to the _________ of the staircase (EXCEPT _________________ – it is special) Non-Metals are found to the _____________ of the staircase Metalloids are the elements _____________ the staircase (EXCEPT ALUMINUM and ASTATINE) 6.4: How the Periodic Table Came to Be Textbook pg 223-224 - In the 1860s, many scientists worked together to sort and organize the elements known at that time. - One scientist stood out for his work with organizing and finding relationships among elements. His name was ______________________________ (a Russian Chemist). Mendeleev is known today as the _____________________________________________! How did Mendeleev organize the periodic table? (1860s – 1870s)? - He made a card for each element known at the time (only 63), stating properties like______________________________________________________________________ - He arranged the 63 cards in order of ____________________________________________ - He started with the ___________________________________, followed by the next ____________________________ - He left spaces _____________________________________________________________ - Mendeleev noticed that when he arranged the elements in order of increasing mass, _________________________________________________________________________ - In a brilliant move, Mendeleev decided to arrange elements with ______________________ _________________________________________________________________________ of the table, still keeping them in order of increasing atomic mass. In order to do this, he had to force new rows of different lengths causing the table to be an ______________________! Is the periodic table today organized like Mendeleev’s table? - To discover this answer, look at all the elements in period 4, then period 5. o _____________________________________________________________________ o _____________________________________________________________________ - The elements in today’s periodic table are organized according to ___________________________ NOT _________________________ 6.4: Patterns in the Periodic Table Metals vs Non-metals Properties Metalloids Metals Non-metals Families of Elements Family (Group) Name Hydrogen: Group # Examples Properties 6.6 - Theories of the Atom Scientific Theory – an expression of our best _______________________ of a phenomenon, based on _________________________ or ____________________. - Theories need to be _______________ as technologies improve and new observations are made. - The theory of the ____________ has changed a lot over time. 400 BCE: An Indivisible Particle Who? Democritus (a Greek Philosopher) - All matter can be divided into ____________________________________ until an indivisible particle is reached. This is an ____________. Atom means “____________________________.” - Based on REASON, not EXPERIMENTATION 450 BCE: Earth, Water, Air, and Fire Who? Aristotle (a Greek Philosopher) - Supported the theory that all matter is made up of four basic substances: earth, water, air, and fire. - This theory was accepted for almost ___________ years. - Based on REASON, not EXPERIMENTATION 1807: The Billiard Ball Model Who? John Dalton (English Scientist and teacher) - Proposed that: o All matter is made up of tiny, indivisible particles called ________________ o All ________________ of an ______________ are identical o Atoms of different elements are ________________________ o Atoms are ______________________ to form new substances in chemical reactions, but they are never ______________ or __________________ - Called “billiard ball model” because he thought an atom was _____ __________________________________________________________________. - Very useful because it explained ______________________________________. - But, it could not explain why some objects___________ each other and other objects _________ each other. 1897: The Plum Pudding Model – The Electron Who? J.J. Thomson - Thomson discovered that some particles were ________________ charged and some were _________________ charged. - Theorized that: o Atoms contain negatively charged particles called ____________________. o Since atoms are _____________, the rest of the atom is a _________________ charged sphere. o - Negatively charged electrons are ____________________________ throughout the atom. Called “The Plum Pudding Model” because the ________________ embedded in an atom resembled raisins in plum pudding. Today, we can think of it as a “Chocolate chip muffin” model. 1909: The Gold Foil Experiment – The Nucleus and the Proton Who? Ernest Rutherford - Tested Thomson’s model of the atom - Performed an experiment involving passing particles through gold foil and observing what happens - Rutherford discovered: o The center of an atom has a _____________ charge. The center is called the __________. It contains most of the atom’s mass but occupies a very _____________ space. o The nucleus is surrounded by a __________ of negatively charged __________________. o Most of the atom is _______________________. o ________________ are positively charged particles contained in the nucleus. o Predicted that there must be a third particle in the nucleus that have approximately the same mass as a proton. 1932: The Neutron Who? James Chadwick (Rutherford’s Student) - Found a particle with ______________ charge - Proposed that: o An atom must be an ___________________ with a tiny dense central nucleus. o The nucleus contains protons (positively charged particles) AND _____________________ (_______________ particles). o The ___________ of a neutron is about the same as a ______________. o Negatively charged electrons ________ rapidly through the empty space around the _____________. o A neutral atom as the same number of ______________ and ___________________. 1913: Electron Orbits Who? Niels Bohr (Danish Scientist) - Electrons occupy ____________________ around the nucleus (much like _____________________________________________________________________________). 6.7: Explaining the Periodic Table What is in the atom? The atom is made up of three ______________________________________________ Subatomic Particle Symbol Charge Mass (u) We can use the periodic table to determine the amounts of these 3 particles contained in each element Atomic Number The periodic table is arranged according to _______________________________ Tells you the ________________________________________ in an atom’s ___________________ Each atom has ________________________________________________________________ Atomic Mass The ___________________________________________________________ Measured in ________________________________________ (u) This is an ___________________________________ value (use two decimal places) Isotope An atom with the __________ number of ______________but a _______________ number of ______________ The atomic mass is really an __________________ mass of all the different isotopes of an atom Example: Isotopes of carbon can have ___________________________ neutrons. But it only ever has __________ protons. Mass Number The _____________________________________________ (to the nearest whole number) The _________________________________________________ in an atom’s nucleus Atomic (Standard) Notation • A standard way to show subatomic particle information # Protons = # Neutrons = # Electrons = Ex: Fluorine #p= #n= #e= TRY: Carbon TRY: Bromine Standard notation: Standard notation: #p= #p= #n= #n= #e= #e= Bohr-Rutherford Diagrams Combines Bohr and Rutherford models of the atom A drawing that shows the _______________ and ________________ of the 3 subatomic particles ____________________ ______________ are __________________________________ and do not move __________________________________ around the nucleus ◦ The first orbital can hold up to _____ electrons ◦ Each orbital after that can hold up to ______ electrons ______________________________ are electrons in the outermost electron shell How to draw: 1. Draw a ______________ for the _______________ • inside, write the number of protons and neutrons 2. Draw a _____________ for each ____________________________ . Add electrons (maximum of _______!) A __________ represents an electron. 3. Draw more shells as needed and add electrons (maximum of ______________!) Practice: Hydrogen Carbon Sulfur Atoms and Ions Lewis Dot Diagrams Simpler diagram of an atom Show only the _____________ (_____________) electrons in an atom Because these are the only electrons that will ____________ Write the element ______________ and draw _________ for its number of valence electrons around the symbol Atoms vs Ions Atoms have an ______________________________ (# protons = # electrons) Most atoms by themselves are not “happy” (because they are not ________________) They want to have their outer orbits ______________________________ with electrons (*like the ___________________!) ATOMS will ___________ or _______________ ELECTRONS to obtain a ________ valence shell **_____________________ DO NOT move! This forms an ion: ______________________________ Because ions have ______________ numbers of protons and electrons, they are not __________ Ions have a positive OR negative ____________________________: IF e- are lost: IF e- are gained: Now has more ____ than ____ Now has more ____ than ____ _________________ charged ion _________________ charged ion Called a _____________ Called an __________ Ex: Sodium Ex: Oxygen Summary of Ionic Charges 1 2 Atoms And Ions In the top of each box, Use Lewis-Dot diagrams to draw each ATOM. In the bottom of each box, use Lewis-Dot diagrams to represent the most common ION formed by each atom. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Questions: 1. What do you notice about the amount of electrons lost/gained in each group? 2. What do you notice about the ionic charge of each group? 3. Which atoms do not form ions? Chapter 7: Chemical Compounds Chemical Formulas of Compounds Chemical Formula Notation that tells the ___________ and ____________ of atoms in a compound Rules for Writing and Reading Chemical Formulas: 1. The number ___ is never written. If there is no number, it’s a ___. 2. The # of atoms is written ________ the element symbol as a _____________________________ ie: H2O means __________________________________________ 3. The # of molecules is written ________________ the formula. ie: 3 H2O means _________________________________ 4. If there are _______________, the subscript number applies to all atoms in __________________. Examples Compound Number of Formula Molecules Li2O 3 CO2 4 Al2(SO4)3 Element Symbols Name of Element Number of Atoms of Each Element How Atoms Combine • Atoms combine to become more ____________ and form ______________________ • Noble gases are already stable because they have a _____________________________________, so they do not __________________ with other elements. • Atoms without a full outer shell of electrons will combine with other atoms to obtain a _____________ _________________________. • There are 3 possible combinations that can occur: 1. Metal and Metal (Alloys) • Metals form ______________ with other metals to form __________________ • Alloys are created by ___________________ two or more metals and then mixing these hot liquids. • These are not _____________________ because the atoms are not _________________________, they are just metals mixed together. • Examples: • _______________ is an alloy of copper and zinc • _______________ is an alloy of gold, nickel, and palladium • ___________________________ is an alloy of iron, nickel, and chromium 2. Metal and Nonmetal (Ionic Compounds) A cation ( ) and an anion ( ) will be _____________ to each other to form an IONIC COMPOUND. We can also think of this as ________________________ from the ________ to the _____________ Held together by ____________________ Naming Rules 1. Write the metal name 2. Write the non-metal name, but change the ending (last syllable) to “_______” Ex: NaCl = BeS = AlN = Writing Chemical Formulas Method 1: Diagrams Use Lewis Dot Diagrams to show how IONIC BONDING occurs. Rules Examples 1. Draw each L-D diagram Na and Cl 2. Use ________________ to show the direction of e- movement 3. Transfer electrons until all atoms are ______________ K and S If needed, add more atoms to obtain stability! Method 2: Using Ionic Charges Rules Example 1. Write the SYMBOL for each element, metal then non-metal. 2. Write the ionic CHARGES above each symbol 3. CRISS-CROSS the numbers to make subscripts DO NOT write the + or – DO NOT write the number 1 4. If necessary, REDUCE the subscripts to the simplest ratio. More examples: a) Aluminum oxide b) Magnesium sulfide c) Lithium bromide d) Potassium nitride e) Calcium phosphide f) Zinc oxide Multivalent Compounds Remember…some metals can have multiple valencies (charges). Iron ( Copper ( Tin ( Lead ( ): 2+ or 3+ ): 1+ or 2+ ): 2+ or 4+ ): 2+ or 4+ Use a roman numeral _____________________ to indicate which charge the ion has. Examples: FeCl2 = FeCl3 = Lead (IV) bromide Lead (II) bromide Tin (II) oxide Tin (IV) oxide Copper (I) nitride 3. Nonmetal + Nonmetal (Molecular Compounds) Formed when ___________________________ join with other ________________________ Electrons are ___________________ between the non-metals o no charges or ions involved! This sharing forms a ______________________________ There is no _________________________ of atoms; they can combine in many different ways. o Oxygen can form O2 (________________________) or O3 (________________). o These molecules act very _________________ from one another, even though their formulas look _______________! Two types of molecules: 1. Molecular Element Contain atoms of the ________________________________ There are _______________ elements that are called __________________________________: They do not naturally exist as _______ atom; they are always ____________! Use the acronym ____________________ to remember these! Naming Rules Use their ___________________________________________________________ 2. Molecular Compound Contain of two or more ____________________________, like ___________________________ Use prefix rules for naming (see below) Naming Rules Many have common names Water = Ammonia = Methane = Hydrogen peroxide = There are also standard rules that use numerical PREFIXES Prefix Using Prefixes 1. Write element names in same order as formula, change ending to “______” (same as ionic) 2. Add _________ to tell the amount of each atom. (Exception: *Do NOT use “________” before the _______ element) Ex: PCl3 C2Br Writing Chemical Formulas Method 1: Drawing Bonding Diagrams Rules Example 1. Draw each L-D diagram N and F 2. Draw a circle around each pair of electrons that are being shared 3. Continue adding bonds and/or atoms until all atoms are full or “happy” Method 2: Use the Molecule Name Rules Example 1. Write the SYMBOL for each element, same order as in Carbon dioxide formula 2. The _________________ in the name become the ____________________ in the formula Carbon monoxide No ionic charges or criss-crossing needed!! 3. NO ______________________! ie: N2O4 and NO2 are ____________________ molecules Diphosphorus tetranitride # of Atoms Chapter 7 Summary Metal and Nonmetal Type of Compound Type of Bond Electron Behaviour Composition Nonmetal and Nonmetal Metal and Metal Standard Gas Tests