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Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one.

Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

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Page 1: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Warm-up 11/21

Watch the video and describe how one scientists changed aspects of the previous theory to make a new one.

Page 2: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Organizing the Periodic Table

Chemists use the properties of elements to

sort them into groups

Page 3: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Warm-up 11/25

• Use the periodic table to find the following information on Fluorine.– Group #– Period– # of Valence Electrons– # of Energy Levels (shells)occupied by the

electrons in Fluorine

Page 4: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Mendeleev’s Periodic Table• 1869- Russian chemist &

teacher published the first table of elements to be widely accepted

• Arranged the elements into rows in order of increasing mass so that elements with similar properties were in the same column

• Left empty spaces where undiscovered elements would fit

Eka aluminum (gallium) predicted it would be a soft metal with a low melting point and a density of 5.9 g/cm3 close match=useful table!

Page 5: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

12/1 Warm-up

• Describe 3 pieces of information that you can get from the periodic table about an element.

Page 6: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

12/2 Warm-up

Determine which of these images is a metal, nonmetal and metalloid and write the clues you used to decide.

Page 7: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

The Modern Periodic Table• An arrangement of elements based on a set of properties that repeat

from row to row• Elements are arranged according to atomic number• 7 rows or periods- each corresponds to a principle energy level- the

# of elements per period varies because the # of available orbitals increases from energy level to energy level

• Elements within a column or group have similar properties• Properties w/in a period change as you move across the row, the

pattern repeats as you move from one period to the next

Page 8: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Periodic Law• When elements are arranged in order of

increasing atomic number, there is a periodic repetition of their physical and chemical properties

Atomic radii decreases

Electronegativity decreases

Page 9: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one
Page 10: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

SodiumPotassium

Page 11: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Metals

• 80% of elements• Good conductors of

heat and electricity• High luster- reflect light• Solids at room

temperature• Ductile

Page 12: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Nonmetals

• Show greater variation in physical properties

• Most are gases at room temp.

• Properties opposite metals– Poor conductors– Brittle

Page 13: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Metalloids

• Show properties similar to metals and nonmetals depending on conditions

Page 14: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Round atomic mass to the nearest whole # to get mass #

Use the atomic # to find the # or protons or electrons (in a neutral atom)

Mass #-Atomic #=neutrons

Page 15: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Representative Groups• Valence electron-

electron that is in the highest occupied energy level of an atom

• Valence electrons play a key role in chemical reactions

• Properties vary across a period because the # of valence electrons increases from left to right

• Elements in a group have similar properties because they have the same # of valence electrons

Page 16: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Valence Electrons• When the highest

occupied energy level of an atom is filled with electrons, the atom is stable and not likely to react.

• Electron dot diagram- a model of an atom in which each dot represents a valence electron

Page 17: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Ionic Bonds• Elements that do not

have complete sets of valence electrons tend to react.

• Some elements achieve stable electron configurations through the transfer of electrons between atoms.

• When an atom gains or loses an electrons the # of protons does not equal the # of electrons this forms an ion

• Ion- charged atom• Formation of an ion

requires energy because an electron must be removed

Anions are named by using part of the element name and the suffix -ide

Page 18: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

To become an ion an elements electron must escape the energy levels by gaining a required about of energy called the ionization energy.

Page 19: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Formation of Ionic Bond

• An ionic bond is an attraction between a cation (metal) and an anion (nonmetal)

• A ionic compound is a compound that contains ionic bonds and the net charge must be zero

Page 20: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Crystal Lattices

Ionic Compounds have high melting points, are poor conductors as

solids (good when melted or in

solution), and shatter when struck with a

hammer.

Page 21: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Covalent Bonds• Nonmetals will

sometimes share electrons to achieve a full set of valence electrons

• A chemical bond in which two atoms share electrons is a covalent bond

• The attraction between the shared electrons and the protons in each nucleus hold the atoms together.

Electron dot formula

Structural Formula

Page 22: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Covalent Bonds• Some atoms

share more than one pair of electrons to reach a full outer shell of electrons.

• Two pairs of electrons- double bond

• Three pairs of electrons- triple bond

Page 23: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Polar Covalent Bonds

• In a covalent compound with more than one type of atom the electrons may not be shared equally

• In general, elements on the right of the periodic table and at the top of groups have a greater attraction for electrons (electronegativity)

A covalent bond in which the electrons are aren’t shared equally is a polar covalent bond

Page 24: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Polar and Nonpolar Molecules

• In a polar covalent bond the atom with the greater attraction for electrons has a partial negative charge and the other atom has a partial positive charge.

• An atom can have a polar bond and not be a polar molecule.

• The type of atoms and its shape determine whether a molecule is polar or not.

Which of these are polar??

Page 25: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Attraction Between Molecules

• There are forces of attraction between molecules they are not strong as ionic or covalent bonds but they are strong enough to hold molecules together in a solid or a liquid

• Attractions between polar molecules are stronger than attractions between non-polar molecules

Page 26: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one
Page 27: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one
Page 28: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Metallic Bonds

• The attraction between the metal cation and the shared electrons around it

• In a metal the valence electrons are free to move among the atoms- this accounts for many of the properties of metals

Page 29: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Chemical Reactions

• In a chemical reaction one or more reactants react to form one or more products

• Chemical Equations are used to represent the process of a chemical reaction.

• Reactants Product

• Mass is neither created or destroyed during a chemical reaction so the number of atoms on either side of the equation must be equal.

Page 30: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one
Page 31: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Balancing Equations• In order to show that mass is

conserved during a chemical reaction the equation must be balanced.

• Equations are balanced by changing the coefficient's (the numbers in front of the formulas)

• NEVER CHANGE THE SUBSCRIPTS- THAT CHANGES THE IDENTITY OF THE REACTANT OR PRODUCT

Page 32: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

TYPES OF REACTIONS

• Synthesis- two or more substances react to form a single substance

• A + B AB• Balance this one

– Na + Cl2 NaCl

Page 33: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Decomposition Reactions

• A reaction in which a compound breaks down into two or more simpler substances.

• AB A + B• Balance this one- H2O H2 + O2

Page 34: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Single Replacement Reaction

• Reaction in which one element takes the place of another.

• A + BC B + AC• Balance this one-

Cu + AgNO3 Ag + Cu (NO3)2

Page 35: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Double Replacement Reaction

• Two different compounds exchange positive ions and form two new compounds

• AB + CD AD + CB

• Try These-PB(NO3)2 + KI PBI2 + KNO3

CaCO3 + HCL CaCL2 + H2CO3

Page 36: Warm-up 11/21 Watch the video and describe how one scientists changed aspects of the previous theory to make a new one

Combustion

A substance reacts rapidly with oxygen often producing heat and light

• Balance these

CH4 + O CO2 + H20

H2 + O2 H2O