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Putting Atoms Together. Chapter 7. Terminology. two or more atoms of the same or different elements that are chemically joined together in a unit. . Molecule – Ex . Air = roughly 80% _______________ molecules, _____ oxygen molecules, and trace amounts of H 2 O and CO 2. nitrogen.
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Putting Atoms Together Chapter 7
Terminology two or more atoms of the same or different elements that are chemically joined together in a unit. Molecule – • Ex. Air = roughly 80% _______________ molecules, _____ oxygen molecules, and trace amounts of H2O and CO2 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 – above/after Superscript Mg2+ Subscript below/after O2= 2 oxygen atoms Elements that exist as molecular elements consisting of 2 atoms.
Molecular compounds Sharing is caring!
What do we call rxn’s that release energy/heat? What do we call rxn’s that require it? Terminology 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
Means electrons “LEAN” or migrate towards one molecule creating partial + and - charges Forces that hold atoms together Represent “potential” energy hydrogen 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. oxygen valence 2 8 sharing of electrons 2 H + 1 OH2O
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.
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
TERMINOLOGY 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 non-metal electrons a particle that has a + or - charge Anion Cation
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.
Draw Diagram from text (pg. 260) • Copy the Bohr-Rutherford • Create a Lewis Dot Diagram
Periodic Table Worksheet REVIEW
Metals non-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. staircase metalloids periods Energylevels shells
columns Families 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 atomicnumber charge
charge valenceelectrons 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). 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 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 ____. 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 gain2 -2 neon
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. • What happens with the electrons in these compounds?
Ionic compounds Names & Formulas
REview 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 non-metal electrons a particle that has a + or - charge Anion Cation
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
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 Potassiumox”ide’
Try these… Lithium oxide Magnesium flouride Sodium chloride Potassium nitride Calcium sulphide Berylium phosphide Lithium bromide Sodium oxide
WRITING chemical FORMULAS for Ionic Compounds given/taken 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. ____________________________! 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 -2 +1 Rb O Ex. Rubidium fluoride +1 -2 Rb O Rb2O1 “backcross it down” “charges it up” _____ _____
Mg+2 N-3 Fr+1 P-3 Ca+2 F-1 Na+1 Cl-1 Fr3P CaF2 Mg3N2 NaCl