Chemistry Definitions

SECTION 1
*compound is a substance that is made of atoms of two or more different elements joined by chemical bonds.
*chemical bond is the force of attraction that holds two atoms together.
*Bond length is the distance between nuclei for two bonded atoms at their minimum potential energy. The bond length of a hydrogen-hydrogen bond is 75 pm.
*bond angle is the angle formed by two bonds tothe same atom.

Three major theories used to determine bond angles are
* the valence shell electron pair repulsion theory, or VSEPR
* the valence bond theory
* the molecular orbital theory

SECTION 2
*Ionic bonding is a type of chemical bonding that results from the electrical attraction between oppositely charged ions.
*Covalent bonding is bonding in which two nuclei shareelectrons.
*POLAR AND NONPOLAR COVALENT BONDS:
In covalent bonds, atoms share electron pairs. If they share them equally, the covalent bond is nonpolar. If the electrons are more strongly attracted to one of the atoms, the covalent bond is polar.
*METALLIC BONDING:
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Metallic bonding is chemical bonding that results from the attraction between metal atoms and the surrounding sea ofelectrons. | | |
*NAMING COMPOUNDS CONTAINING POLYATOMIC IONS:
Some compounds contain polyatomic ions—a charged group of covalently bonded atoms. Most of these groups are negatively charged, and many contain oxygen.

Common polyatomic ions include:
* ammonia, NH4+
* nitrate, NO3-
* carbonate, CO32-
* sulfate, SO42-
* and phosphate, PO43-


SECTION 3.*NAMING IONIC COMPOUNDS:When naming these compounds, write the name of the cation followed by the name of the anion.
The naming system of binary ionic compounds involves combining the names of the compound's positive and negative ions.

Steps for naming ionic compounds made up of two elements:
* Write the name of the cation.
* Write the name of the anion.
Naming Covalently-BondedCompounds | |
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The naming system of covalently-bonded compounds involves combining the names of the compound's elements.Steps for naming ionic compounds made up of two elements: * Write the name of the less electronegative element. * Write the name of the more electronegative element. Naming Monatomic Ions | |
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An ion formed from a single atom is known asa monatomic ion.When an element gains one or more electrons, it becomes an anion. The negatively charged anion tends to be only slightly larger than the element itself. To name a monatomic anion, write the name of the element, dropping the ending and adding "–ide" to the root, then write "anion."When an element loses one or more electrons, it becomes a cation. The positively charged cation will besmaller than the element from which it came. To name a monatomic cation, write the name of the element, followed by "cation." In the case of metals, use stock nomenclature as needed. |
| *NAMING COMP. IN THE STOCK SYSTEM | *NAMING COMP. USIBG THE STO |
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Transition metals may form several cations, each with a different charge. In cases like this, the cation name must befollowed by a Roman numeral in parentheses. The Roman numeral shows the cation's charge.Steps for naming compounds made up of two elements using the stock system: * Write the name of the cation. * In parentheses, write the cation's charge. * Write the name of the anion. |
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A chemical formula is the combination of chemical symbols and numbers that represent a substance. |*NAMING COMP. USING NUM PREFIXES
Some compounds can be named using the prefix system. The prefix indicates the number of atoms of the element to which the prefix is attached.

Common numerical prefixes include:
* mono–
* di–
* tri–
* tetra–
* penta–
An ionic compound is a substance composed of ions bound together by electrostatic attraction.

A molecular compound...