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Chapter 7
Chemical Bonding
Question | Answer |
---|---|
the number of electrons found in the outermost energy level of an atom---in the s and p orbitals | valence electrons |
electrons within an atom responsible for chemical bonding | valence electrons |
when sodium combines chemically with chlorine, how does sodium become more stable | by losing an electron to chlorine the atom becomes a positive ion and has a total of 8 valence electrons |
when chlorine combines chemically with sodium, how does chlorine become more stable | by gaining an electron the atom becomes a negative ion with a total of 8 valence electrons |
when a neutral atom loses an electron the atom is transformed into __________ | a positive ion |
a positive ion is called a ________ | cation |
when a neutral atom gains an electron the atom is transformed into _________ | a negative ion |
a negative ion is called an | anion |
the Lewis structure for sodium chloride is | [Na]^+[Cl]^- |
an ion is formed when an atom either __________ or ____________ an electron | loses, gains |
in the formation of sodium chloride, what keeps the ions together | the attraction the positively charged ion has for the negatively charged ion and vice versa |
an _______________ is formed when an electron is transferred from one atom to another atom | ionic bond |
atoms held together by ionic bonds form a ________ __________ | crystal structure |
explain how magnesium and fluorine combine chemically | the metallic atom will transfer a total of two electron. one electron will be transferred to two separate fluorine atoms. the nonmetal atoms become negatively charged and the other atom becomes a positive ion |
Why do atoms transfer and accept ions from each other | to fulfill the octet rule meaning that the atom or ion has at least 8 valence electrons |
what is the octet rule | atoms combine chemically in order to have a full outside energy level or have at least 8 electrons in the outside energy level |
by what process is a fluorine molecule formed | the two f atoms have 7 valence electrons, six electrons are paired and one unpaired. by the sharing the tow unpaired electrons both atoms in effect have 8 electrons in the outside energy level |
the ___________ _________ represent a pair of electrons being shared between two atoms | bond line |
the electrons within an atom that are not involved in the bonding process are called the _________ ______ | none bonding pair |
the sharing of valence electrons between two atoms is called ________ ________ | covalent bonding |
a covalent compound is sometimes called a _______ ________ | molecular compound |
ionic compounds are not made of ___________ | molecules |
what must happen in order for two oxygen atoms and one carbon atom to form a molecule | the carbon atom has two pairs of shared electrons with each oxygen atom |
draw the Lewis structure for carbon dioxide molecule | O=C=O |
when two atoms share a total of 4 electrons (two pairs of shared electrons) the bond is called a ________ | double bond |
when two atoms share a total of 6 electrons (three pairs of shared electrons) the bond is called a ______ | triple bond |
list the steps involved in writing a Lewis structure | 1. count the number of valence electrons involved for each atom in the compound. 2. determine the number of needed electrons for full octets 3. needed electrons - valence electrons then divide by 2-----gives you the total number of bonds needed in t |
compound forming crystals | ionic compounds |
compound having high melting and boiling points | ionic compounds |
compounds that shatter when struck | ionic compounds |
compounds that are soluble in water | ionic compounds |
compounds that are electrolyte | ionic compounds |
substance that dissolve in water releasing ions and conducting electricity | electrolytes |
compounds that are not electrolyte | covalent compounds |
compounds that are gases, liquids or solids | covalent compounds |
compounds that generally don't dissolve in water | covalent compounds |
compounds that are often flammable | covalent compounds |
metals have __________ electrons | free mobile valence |
metals form a weak ________ ________ similar to ionic compounds | crystalline structure |
because of the weak crystalline structure of metals, the metal itself can be considered to be ___________ and ___________ | malleable, ductile |
mixtures composed of two or more elements (usually metals) are known as ____________ | alloys |
alloys have properties that are often ___________ to those of their component elements | superior |
compounds that are flammable are usually __________ compounds | covalent |
atoms that share electrons equally form a _________ bond | nonpolar covalent |
atoms that share electrons unequally, form a ________ bond | polar covalent |
the bond formed by the sharing of a single pair of electrons is called a __________ bond | single covalent |
the bond formed by the sharing of 2 pairs of electrons is called a ____________ bond | double covalent |
the atoms held together by sharing electrons are joined by ___________________ . | covalent bond |
a neutral group of atoms joined together by covalent bond is a _______________ | molecule |
a compound composed of molecules is called a ______ | molecular compound |
_______________________ compounds tend to have relatively lower melting and boiling points than ionic compounds | molecular compound |
a _________________ shows how many atoms of each element a molecule contains | molecular formula |
in covalent bonds, electron sharing usually occurs so that atoms attain the ________________ of noble gases | electron configuration |
a pair of valence electrons that is not shared between atoms is called an ________________ | unshared pair |
a _________________________________________ is a covalent bond in which one atom contributes both bonding electrons. | coordinate covalent bond |
a _________________________ is a tightly bound group of atoms that has a positive or negative charge and behaves as a unit | polyatomic ion |
the energy required to break the bond between two covalently bonded atoms is known as the _____________________________________ | bond dissociation energy |
a large bond dissociation energy corresponds to a stong __________________ | covalent bond |
a _____________________- is a structure that occurs when it is possible to draw two or more valid electron dot structures that have the same number of electron pairs for a molecule or ion. | resonance structure |
the octet rule cannot be satisfied in molecules whose total number of valence electrons is and _____________________ | odd number |
when two atoms combine, it is assumed that their atomic orbitals overlap to produce a _______________, or orbitals that apply to the entire molecule | molecular orbitals |
a molecular orbital that can be occupied by two electrons of a covalent bond is called a __________________ | bonding orbitals |
when two atomic orbitals combine to form a molecular orbital that is symmetrical around the axis connecting the tow atomic nuclei, a ________________is formed | sigma |
___________________ bond can be formed when 2 s or 2 orbitals overlap | sigma |
in a ___________________, the bonding electrons are most likely to be found in sausage-shaped regions above and below the bond axis of the bonded atoms | pi bonds |
which type of molecular bond is considered to be the weakest | pi bonds |
in _____________________, several atomic orbitals mix to form the same total number of equivalent hybrid orbitals. | hybridization |
____________________ bonds are attractive forces in which a hydrogen covalently bonded to a very electronegative atom is also weakly bonded to an unshared electron pair of another electronegative atom | hydrogen |
____________________- bonds are the strongest of the intermolecular forces. | hydrogen |