Chemistry Chapter 2

Nucleus

Where is the mass of an atom concentrated?

Protons and Neutrons

Where does the mass of an atom come from?

Mass number

Number of protons and neutrons in an atom

Atomic number

Number of protons in atom

Atomic symbol

Abbreviation used to represent atom in chemical formulas

Isotopes

Atoms that have the same number of electrons, the same number of protons, but different numbers of neutrons

Number of neutrons

Mass number - number of protons

Ions

Have a charge; the number of electrons is either greater than, or less than, the number of protons

Cations

Positively charged. They have fewer electrons than in the neutral atom

Anions

Negatively charged. Have more electrons than in the neutral atom

Molecular formula

A representation of a molecule showing the number and types of atoms present

Structural Formula

Similar to the molecular formula but shows how atoms are connected in a molecule

Ionic Bonds

Can be transferred from one atom to another.

Ionic bonds are formed by the electrostatic forces between anions and cations

Covalent Bonds

Electrons can be shared between two atoms.

Covalent bonds are formed when one or more pairs of electrons are shared between two atomic nuclei.

remains unchanged

In an ordinary chemical reaction: the nucleus of each atom

shared between atoms to form chemical bonds

In an ordinary chemical reaction: electrons can be

Polyatomic ions

Groups of atoms bonded together into electrically charged molecules

cation followed by anions

Ionic Compounds Nomenclature

cation + nonmetal base + ide

Ionic Compounds Nomenclature (monatomic anions)

cation + polyatomic ion’s same name

Ionic Compounds Nomenclature (polyatomic anions)

name of cation + (charge of cation (metal) in roman numerals in parentheses) + base name of anion (nonmetal) + ide

Transition metal ionic compound nomenclature

Molecular Compounds

Discrete, neutral molecules formed by a combination of nonmetals.

Form when atoms share electrons between nuclei.

Are usually gases and liquids with low boiling points or solids with low melting points

Molecular Compounds Nomenclature

More metallic element - the one toward the left/bottom of the periodic table - is named first.

More non-metallic element - the one toward the right/top of the periodic table - is named last with the suffix -ide

Molecular compound

Two or more nonmetals

True

Never use prefix mono- on the first element

Prefix + name of 1st element + prefix + base name of 2nd element + -ide

Molecular Compound Nomenclature

Binary Acids

Two element acids

Binary acids

Hydro + base name of nonmetal + -ic

Oxyacids

contain oxygen

Hydrogen

Class of substances known as acids

Polyatomic ion name ends in -ate

base name of oxyanion + -ic + acid

Polyatomic ion name ends in -ite

base name of oxyanion + -ous + acid