Download Chapter 4

PHYSICAL SCIENCE
CHAPTER 5
THE STRUCTURE OF MATTER
5-1 Compounds and Molecules
Objectives:
• Distinguish between compounds and mixtures.
• Relate the chemical formula of a compound to the relative numbers of or ions present in the compound.
• Use models to visualize a compound’s chemical structure.
• Describe how the chemical structure of a compound affects its properties.
A. What Are Compounds?
1. _____________________________________________ distinguish compounds from mixtures.
2. The attractive forces that hold different atoms or ions together in compounds are called
________________________________________________.
3. A compound always has the same chemical ______________________________.
4. A ________________________________________________ shows the types and numbers of
atoms or ions making up the simplest unit of the compound.
5. Compounds are always made of the same __________________________ in the same proportion.
6. Chemical _________________ shows the arrangement of bonded atoms or ions within a substance.
7. The term ____________________________________ gives the average distance between the
nuclei of two bonded atoms.
8. The term ______________________________________ describes the angle formed by two bonds.
B. Models of Compounds
1. The __________________________________________ gives an idea of bond lengths and angles.
2. The _______________________________________________ shows the structures of compounds.
3. The _______________________________________________ shows the arrangement of atoms in
a compound, but is inadequate for demonstrating bond angle and length.
C. How Does Structure Affect Properties?
1. Compounds with ___________________________________________________ are strong solids.
2. Table salt [NaCl] is an example of a network structure that is made of ______________________.
3. Sugar is an example of a network structure that is made of ________________________________.
D. Summary
1. Atoms or ions in compounds are joined by chemical bonds.
2. A compound’s chemical formula shows which atoms or ions it is made of.
3. A model represents a compound’s structure visually.
4. Substances with network structures are usually strong solids with high melting and boiling points.
5. Substances made of molecules have lower melting and boiling points.
6. Whether a molecular substance is a solid, a liquid, or a gas depends on the attractions between its
molecules at room temperature.
5-2 Ionic and Covalent Bonding
Objectives:
• Explain why atoms sometimes join to form bonds.
• Explain why some atoms transfer their valence electrons to form ionic bonds while other atoms share
valence electrons to form covalent bonds.
• Differentiate between ionic, covalent, and metallic bonds.
• Compare the properties of substances with different types of bonds.
A. What Holds Bonded Atoms Together?
1. The electrons in the outermost energy level of an atom are called “_________________________”.
2. It is only the valence electrons that are involved in ______________________________________.
3. When atoms bond, their electronic structure is similar to a ________________________________.
• Example: two ___________________________________________ atoms bonded together.
4. Bonds can __________________ and _____________________ to some degree without breaking.
B. Ionic Bonds
1. An ionic bond is formed by the attraction between two oppositely charged ___________________.
a)
Atoms of metal elements form ______________________ charged ions [_______________].
b)
Atoms of nonmetals form __________________________ charged ions [_______________].
2. _______________________________________ are formed by the permanent transfer of electrons.
3. Ionic compounds form networks [______________________________] not molecules.
4. A _____________________________________ gives the lowest ratio of ions in a crystal or unit of
the compound. [NaCl]
5. When _____________________ or ________________________________________, ionic
compounds conduct electricity.
C. Metallic Bonds
1. In __________________________________________, the electrons are loosely held and are free
to move from atom to atom [______________________________________________].
2. Metallic bonding explains why metals are __________________________________ and conduct
___________________________________________________.
D. Covalent Bonds
1. Compounds that are made up of __________________________________ have covalent bonding.
2. Covalent compounds can be __________________, __________________, or ________________.
3. Most covalent compounds have ___________ melting points and ___________ conduct electricity.
4. Atoms joined by covalent bonds __________________________ electrons.
5. In a structural formula,:
a)
a single line drawn between two atoms represents a ________________________________
where the atoms share two electrons.
b)
a double line drawn between two atoms represents a _______________________________
where the atoms share four electrons.
c)
a triple line drawn between two atoms represents a _________________________________
where the atoms share three electrons.
6. The more electrons shared, the ________________________________ the bond.
7. Atoms do not always share electron equally resulting in a _________________ covalent molecule.
E. Polyatomic Ions
1. A polyatomic ion is an ____________ made of two or more atoms
_________________________________________ and that act like a single ion.
2. ______________________________________________ group the atoms of a polyatomic ion in a
chemical formula.
3. Example: (NH4)2SO4 instead of N2H8SO4
F.
Summary
1. Atoms bond when their valence electrons interact.
2. Cations and anions attract each other to form ionic bonds.
3. When ionic compounds are melted or dissolved in water, moving ions can conduct electricity.
4. Atoms in metals are joined by metallic bonds.
5. Metals conduct electricity because electrons can move from atom to atom.
6. Covalent bonds form when atoms share electron pairs. Electrons may be shared equally or
unequally.
7. Polyatomic ions are covalently bonded atoms that have either lost or gained electrons. Their
behavior resembles that of simple ions.
5-3 Compound Names and Formulas
Objectives:
• Name simple ionic and covalent compounds.
• Predict the charge of a transition metal cation in an ionic compound.
• Write chemical formulas for simple ionic compounds.
• Distinguish a covalent compound’s empirical formula from its molecular formula.
A. Naming Ionic Compounds
1. When naming ____________________________________________________________:
a)
the name of the cation [_________________________________________] is given first.
b)
the name of anion [_______________________________________] is given second with the
suffix “_______”.
2. If the cation has more than one possible charge, the charge is given by using a small
______________________________________________________________________.
3. To determine the charge on a transition metal ___________________________, the charge on the
anion(s) must be added up and algebraically balanced with the cation.
B. Writing Formulas for Ionic Compounds
1. Board
C. Naming Covalent Compounds
1. Numerical prefixes are used to name covalent compounds of two elements.
NUMBER OF
PREFIX
ATOMS
_______________ Mono_______________ Di_______________ Tri_______________ Tetra_______________ Penta_______________ Hexa_______________ Hepta_______________ Octa_______________ Nona_______________ DecaD. Chemical Formulas for Covalent Compounds
1. A compound’s simplest formula is its ________________________________________________.
2. Different compounds _______________________________________ the same empirical formula.
3. _______________________________________________ are determined from empirical formulas
4. A _______________________________________________ is a chemical formula that reports the
actual numbers of atoms in one molecule of a compound.
E. Summary
1. To name an ionic compound, first name the cation and then the anion.
2. If an element can form Cations with different charges, the cation name must include the ion’s
charge. The charge written as a Roman numeral in parentheses.
3. Prefixes are used to name covalent compounds made of two different elements.
4. An empirical formula tells the relative numbers of atoms of each element in a compound.
5. A molecular formula tells the actual numbers of atoms in one molecule of a compound.
6. Covalent compounds have both empirical and molecular formulas.
5-4 Organic and Biochemical Compounds
Objectives:
• Describe how carbon atoms bond covalently to form organic compounds.
• Identify the names and structures of groups of simple organic compounds and polymers.
• Identify what the polymers essential for life are made of.
A. Organic Compounds
1. An _____________________________________________ is a covalently bonded compound that
contains carbon and almost always hydrogen.
2. Carbon atoms form _______________________________ covalent bonds in organic compounds.
3. An organic compound made of only carbon and hydrogen is called a
_______________________________________.
4. Other common elements found in organic compounds include _______________________,
_______________________, _______________________, and _______________________.
5. Carbon atoms have ___________________________ valence electrons to use for bonding.
6. The ____________________ are the group of hydrocarbons containing only single covalent bonds.
a)
When all of the carbons in an alkane are in a single line, the alkane is referred to as a
____________________________________________.
b)
The first 10 alkanes are:
n-ALKANE
MOLECULAR
CONDENSED STRUCTURAL
FORMULA
FORMULA
______________________________ CH4
CH4
______________________________ C2H6
CH3CH3
______________________________ C3H8
CH3CH2CH3
______________________________ C4H10
CH3(CH2)2CH3
______________________________ C5H12
CH3(CH2)3CH3
______________________________ C6H14
CH3(CH2)4CH3
______________________________ C7H16
CH3(CH2)5CH3
______________________________ C8H18
CH3(CH2)6CH3
______________________________ C9H20
CH3(CH2)7CH3
______________________________ C10H22
CH3(CH2)8CH3
c)
The pattern for the alkanes is _________________________________.
7. __________________________________________ are hydrocarbons with a double bond.
8. Alcohols have __________________________________ groups.
9. Because of their structure, alcohols behave similarly to ____________________________.
B. Polymers
1. Polymers are ________________________________________________________________
made of many smaller bonded units.
2. Many polymers have _________________________________________ subunits.
3. ___________________________________ is a polymer made of many “poly” ethane molecules.
4. The base unit, in this case C2H4, is called the __________________________________________.
5. Rubber, wood, cotton, wool, starch, protein, and DNA are all _____________________ polymers.
6. Plastics and fibers are ____________________________________________ polymers.
C. Biochemical Compounds
1. Biochemical compounds are _______________________________________________________
organic compounds that are very important to living things.
2. A _________________________________________________ is any organic compound that is
made of carbon, hydrogen, and oxygen and that provides nutrients to the cells of living things.
3. A __________________________________ is a biological polymer made of bonded amino acids.
4. An amino acid is any one of ____________________ naturally occurring organic molecules that
combine to form proteins.
5. _______________________________ is a protein with a complex, double helix structure.
D. Summary
1. Alkanes have C-C and C-H bonds
2. Alkenes have C=C and C=H bonds.
3. Alcohols have on or more –OH groups.
4. Polymers from when small organic molecules bond to form long chains.
5. Biochemical compounds are polymers important to living things.
6. Sugars and starches are carbohydrates that provide energy.
7. Amino acids bond to form polymers called proteins.
8. DNA is a polymer shaped like a twisted ladder.