PUTTING ATOMS TOGETHER Chapter 7 TERMINOLOGY Molecule – two or more atoms of the same or different elements that are chemically joined together in a unit. nitrogen 20% • Ex. Air = roughly 80% _______________ molecules, _____ oxygen molecules, and trace amounts of H2O and CO2 TERMINOLOGY notation that indicates the type and number Chemical Formula – of atoms in a pure substance above/after in chemistry •Superscript - small numbers written ____________, usually indicates a charge Mg2+ below/after tells us how many • Subscript – small number ___________, atoms there are O2 = 2 oxygen atoms Diatomic Elements – Elements that exist as molecular elements consisting of 2 atoms. *7 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. non-metal • Involves two _______________ (includes hydrogen) elements joining together and sharing valence electrons to fill their ________ energy level their outer __________________ (shell). 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 Illustration to the right hydrogen shows two __________ molecules and a single oxygen _______ molecule. Hydrogen wants to have a full valence ________ shell (first shell 2 can hold a max. of __) meanwhile the oxygen atom also wants to have a full valence shell (2nd shell 8 Therefore a can hold __). sharing of electrons ____________________ occurs. 2H + 1O H2O A key aspect of molecular compounds is the fact they are dependent____ on arrangement ______________________ ____________________. Only certain combinations in __________ are found in nature. fixed _______________________ amounts Ex. O2 = Oxygen Gas, meanwhile O3 = Ozone •The above example highlights the fact that a change in configuration ______________________________________ dramatically changes the compound and how it affects us. ______________________________________________ These molecules can be drawn as Bohr-Rutherford __________________________________________ diagrams or as Lewis dot diagrams ____________________________________ 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. IONIC COMPOUNDS TERMINOLOGY Compound consisting of a positively charged (cation) and • Def. negatively charged (anion) ion. metal non-metal • Involves a ___________ + a _____________ joining giving away its ___________ valence together, with the metal _____________ non-metal taking them. electrons and the __________ _________ a particle that has a + or - charge Def. Ion –_________________________________ 2 forms Anion = Negative 1.) _________ Cation = Positive 2.) _________ 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. + Charge (Protons) - Charge (Electron) Ionic charge Sodium Sodium Chlorine Chlorine Atom, Na Ion, Na+ Ion, Cl- Atom, Cl 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 are located on the left side of the 1. _______ non-metals located on the right periodic table, with __________ staircase that side. They are separated by a “________” touches the __________. metalloids periods and tell us 2. Horizontal rows are known as ________ shells an element the number of Energy ______ levels _____ or ______ has. Families or groups are vertical ________ columns on the 3. ________ periodic table and tell us how many valence electrons an element has. _________ 4. ATOMS have the same number of Protons as atomic _______, number so their charge is neutral, this they do ______ charge information is detailed in the ______. charge because 5. IONS have a positive or negative _______ they have given up their valence _______ electrons _________ or taken valence electrons from an atom of another element in order to fill/empty their outer energy shell. cations (think the t looks 6. Positive ions are known as _______ anions (has two like a +) while negative ions are called _______ n’s for negative). 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 • Symbol = • Period # = • # of energy levels = • Group # = • # of Valence Electrons = • Member of the _____________ Family • Number of Neutrons = • Draw a Lewis Dot diagram FLUORINE ATOM ION REVIEW a) An ION of fluorine is going to mimic (look like) an atom Neon of ______. b) An ION of beryllium is going to mimic an atom of Helium __________________. phosphorus has to gain 3 electrons to c) An ION of ____________ -3 mimic argon. Its ionic charge will be ____. d) An ION of Aluminum _________ has to give up 3 electrons in order to mimic an atom of neon. Its +3 charge will be ___. gain ___ 2 electrons to e) An Ion of Oxygen has to ____ neon Its ionic charge will be ___. -2 mimic _____. 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 • Def. negatively charged (anion) ion. metal non-metal • Involves a ___________ + a _____________ joining giving away its ___________ valence together, with the metal _____________ non-metal taking them. electrons and the __________ _________ a particle that has a + or - charge Def. Ion –_________________________________ 2 forms Anion = Negative 1.) _________ Cation = Positive 2.) _________ NAMING Ionic compounds are easily identified by the presence metal (first term). Any time you see a metal as of a ___________ the first term, you should automatically be thinking NUMERICAL IONIC! Additionally, there is never a __________________ reference in the compound name (so no PREFIXES _________________). The nice thing about naming Ionic DO NOT need to worry about molecules is we __________ numbers (subscripts). Example K2O 1)Determine how many elements (each capital letter represents a new element) are present in the compound 2 (_______) and locate them on the periodic table. Is there a metal..? If so it must be a Ionic Compound. 2) Identify which of the elements is the metal (it must go Potassium first). __________________ 3) Identify the non-metal element (it goes 2nd). Oxygen ____________________ 4) Write the name of the metal, than the name of the nonmetal (but change the ending of the non-metal to Potassium _____________ oxide “IDE”). ___________ Try these… Li2O Lithium oxide CaS Calcium sulphide MgF2 Magnesium flouride Be3P2 Berylium phosphide NaCl K3N Sodium chloride Potassium nitride LiBr Na2O Lithium bromide Sodium oxide WRITING CHEMICAL FORMULAS FOR IONIC COMPOUNDS given/taken and electrical Since the electrons are ____________ charges _______ are present we need to reference the Periodic Table in order to determine how many of each element there is going to be. 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 +1 -2 element Rb O Ex. +1 -2 Rb O Rubidium “charges it up” _____ _____ “backcross it down” fluoride Rb2O1 Compound Sodium chloride Magnesium nitride Calcium fluoride Francium phosphide CHARGE Na+1 Cl-1 Mg+2 N-3 Ca+2 F-1 Fr+1 P-3 FORMULA NaCl Mg3N2 CaF2 Fr3P