Putting Atoms Together Chapter 7

Terminology Molecule – Ex. Air = roughly 80% _______________ molecules, _____ oxygen molecules, and trace amounts of H2O and CO2 two or more atoms of the same or different elements that are chemically joined together in a unit. nitrogen 20%

Terminology notation that indicates the type and number of atoms in a pure substance Chemical Formula – - small numbers written ____________, in chemistry usually indicates a charge  – small number ___________, tells us how many atoms there are  Diatomic Elements – Superscript above/after Mg2+ Subscript below/after O2 = 2 oxygen atoms Elements that exist as molecular elements consisting of 2 atoms.

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Molecular compounds Sharing is caring!

Terminology What do we call rxn’s that release energy/heat? What do we call rxn’s that require it?   Molecular Compounds – Compound consisting of two or more different elements with neutral charges that are bonded together. Involves two _______________ (includes hydrogen) elements joining together and sharing their ________ electrons to fill their outer __________________ (shell). non-metal valence energy level A simulation of the reaction: 2H2 + O2   ®    2H2O  

hydrogen oxygen valence 2 8 sharing of electrons Means electrons “LEAN” or migrate towards one molecule creating partial + and - charges Forces that hold atoms together Represent “potential” energy Illustration to the right shows two __________ molecules and a single _______ molecule. Hydrogen wants to have a full ________ shell (first shell can hold a max. of __) meanwhile the oxygen atom also wants to have a full valence shell (2nd shell can hold __). Therefore a ____________________ occurs. hydrogen oxygen valence 2 8 sharing of electrons 2 H + 1 O  H2O

dependent on arrangement fixed amounts A key aspect of molecular compounds is the fact they are ______________________ ____ ____________________. Only certain combinations in __________ _______________________ are found in nature. Ex. The above example highlights the fact that a change in ______________________________________ dramatically changes the ______________________________________________ dependent on arrangement fixed amounts O2 = Oxygen Gas, meanwhile O3 = Ozone configuration compound and how it affects us.

Bohr-Rutherford Lewis dot diagrams These molecules can be drawn as __________________________________________ diagrams or as ____________________________________ with the shared pair of electrons represented by a _____, 2 pairs by a ______, or 3 sets of shared electrons by _____. The most that will ever be shared is 3. Bohr-Rutherford Lewis dot diagrams

Ionic Compounds

TERMINOLOGY metal Cation Anion Compound consisting of a positively charged (cation) and negatively charged (anion) ion. Def. Involves a ___________ + a _____________ joining together, with the metal _____________ its ___________ _________ and the __________ taking them. Def. Ion –_________________________________  2 forms 1.) _________ = Positive 2.) _________ = Negative metal non-metal giving away valence electrons non-metal a particle that has a + or - charge Cation Anion

Why does the metal always give away its valence electrons and the non-metal always take them? Think about this silently (use your notes or textbook as a reference)

ANSWER It is easier for a metal to give up 3 or 4 electrons than try to take enough to fill its valence shell. For non-metals, they generally only need 1 or 2 extra’s to fill their shells, so it is easier for them to take 2 than give up 6.

Sodium Atom, Na Sodium Ion, Na+ Chlorine Ion, Cl- Chlorine Atom, Cl   Sodium Atom, Na Sodium Ion, Na+ Chlorine Ion, Cl- Chlorine Atom, Cl + Charge (Protons) - Charge (Electron) Ionic charge

Draw Diagram from text (pg. 260) Copy the Bohr-Rutherford Create a Lewis Dot Diagram

Sodium Ion, Na+ Chlorine Ion, Cl-

HW  Q 1-8 on page 261

Periodic Table Worksheet REVIEW

Metals 1. _______ are located on the left side of the periodic table, with __________ located on the right side. They are separated by a “________” that touches the __________. 2. Horizontal rows are known as ________ and tell us the number of ______ _____ or ______ an element has. non-metals staircase metalloids periods Energy levels shells

Families columns 3. ________ or groups are vertical ________ on the periodic table and tell us how many valence _________ an element has. 4. ATOMS have the same number of Protons as they do ______ _______, so their charge is neutral, this information is detailed in the ______. electrons atomic number charge

charge valence electrons cations anions 5. IONS have a positive or negative _______ because they have given up their _______ _________ or taken valence electrons from an atom of another element in order to fill/empty their outer energy shell. 6. Positive ions are known as _______ (think the t looks like a +) while negative ions are called _______ (has two n’s for negative). valence electrons cations anions

Magnesium Atom Symbol = Period # = # of energy levels = Group # = # of Valence Electrons = Member of the _____________ Family Draw a Bohr-Rutherford Diagram

Lithium Atom Symbol = Period # = # of energy levels = Group # = # of Valence Electrons = Member of the _____________ Family Draw a Lewis-Dot Diagram

Argon Atom Symbol = Period # = # of energy levels = Group # = # of Valence Electrons = Member of the _____________ Family Number of Neutrons = Draw a Bohr-Rutherford Diagram

Fluorine Atom Symbol = Period # = # of energy levels = Group # = # of Valence Electrons = Member of the _____________ Family Number of Neutrons = Draw a Lewis Dot diagram

ION REVIEW Neon Helium phosphorus -3 a) An ION of fluorine is going to mimic (look like) an atom of ______. b) An ION of beryllium is going to mimic an atom of __________________. c) An ION of ____________ has to gain 3 electrons to mimic argon. Its ionic charge will be ____. Neon Helium phosphorus -3

Aluminum d) An ION of _________ has to give up 3 electrons in order to mimic an atom of neon. Its charge will be ___. e) An Ion of Oxygen has to ____ ___ electrons to mimic _____. Its ionic charge will be ___. +3 gain 2 neon -2

Calcium Atom Symbol = Atomic # = # of Protons = # of Electrons = Ionic Charge = Atomic Mass = Number of Neutrons = Draw a Bohr-Rutherford Diagram

Oxygen ION Symbol = Atomic # = # of Protons = # of Electrons = Ionic Charge = Atomic Mass = Number of Neutrons = Draw a Bohr-Rutherford Diagram

chlorine ION Symbol = Atomic # = # of Protons = # of Electrons = Ionic Charge = Atomic Mass = Number of Neutrons = Draw a Bohr-Rutherford Diagram

aluminum ION Symbol = Atomic # = # of Protons = # of Electrons = Ionic Charge = Atomic Mass = Number of Neutrons = Draw a Bohr-Rutherford Diagram

Potassium ION Symbol = Atomic # = # of Protons = # of Electrons = Ionic Charge = Atomic Mass = Number of Neutrons = Draw a Bohr-Rutherford Diagram

Questions from reading How do atoms become more stable? When metals mix with another metal is it called an ________. When metals mix with non-metals it is called an __________ compound. What happens with the electrons in these compounds? When two non-metals mix it is called an ____________ compound.

Ionic compounds Names & Formulas

REview metal Cation Anion Compound consisting of a positively charged (cation) and negatively charged (anion) ion. Def. Involves a ___________ + a _____________ joining together, with the metal _____________ its ___________ _________ and the __________ taking them. Def. Ion –_________________________________  2 forms 1.) _________ = Positive 2.) _________ = Negative metal non-metal giving away valence electrons non-metal a particle that has a + or - charge Cation Anion

NAMING Ionic compounds are easily identified by the presence of a ___________ (first term). Any time you see a metal as the first term, you should automatically be thinking IONIC! Additionally, there is never a __________________ reference in the compound name (so no _________________). The nice thing about naming Ionic molecules is we __________ need to worry about numbers (subscripts). metal NUMERICAL PREFIXES DO NOT

2 Potassium Oxygen Potassium ox”ide’ Example  K2O Determine how many elements (each capital letter represents a new element) are present in the compound (_______) and locate them on the periodic table. Is there a metal..? If so it must be a Ionic Compound. Identify which of the elements is the metal (it must go first). __________________ Identify the non-metal element (it goes 2nd). ____________________ Write the name of the metal, than the name of the non-metal (but change the ending of the non-metal to “IDE”). ___________ _____________ 2 Potassium Oxygen Potassium ox”ide’

Try these… Li2O MgF2 NaCl K3N CaS Be3P2 LiBr Na2O Lithium oxide   CaS Be3P2 LiBr Na2O Lithium oxide Magnesium flouride Sodium chloride Potassium nitride Calcium sulphide Berylium phosphide Lithium bromide Sodium oxide

WRITING chemical FORMULAS for Ionic Compounds Since the electrons are ____________ and electrical _______ are present we need to reference the Periodic Table in order to determine how many of each element there is going to be. ____________________________! given/taken charges THE CHARGES MUST BALANCE

Step 1: Locate the elements in the Periodic Table- ensure one is a metal, and one is a non-metal. Write down their chemical symbol. Step 2: Determine the “charge” each element carries when its forms an ionic bond (remember: STABLE) Step 3: Backcross the “charges“ to SUBSCRIPTS for each element +1 -2 Rb O Ex. Rubidium fluoride +1 -2 Rb O Rb2O1 “charges it up” _____ _____  “backcross it down”

Compound Sodium chloride Magnesium nitride Calcium fluoride Francium phosphide CHARGE   FORMULA Na+1 Cl-1 Mg+2 N-3 Ca+2 F-1 Fr+1 P-3 Mg3N2 CaF2 Fr3P NaCl