CHEMICAL BONDS AND COMPOUNDS Flashcards
Four periodic table sections
- Representative Elements
- Noble - gas Elements
- Transition Elements
- Inner Transition Elements
Compounds are divided into two broad categories:
Ionic compounds
Molecular compounds (Covalent)
Note: Certain combinations of elements produces ionic compounds, some other combinations form molecular compounds
the attractive force that holds two atoms together in a more complex unit
Chemical bond
note: It is important to note that most bonds are not 100% ionic or 10% covalent
Two types of chemical bond
Ionic bonds
Covalent bonds
formed through transfer of one or more electrons from one atom or group of atoms to another
Ionic bonds
formed through the sharing of one or more pairs of electrons between two atoms
Covalent bonds
There are two fundamental concepts to understanding ionic and covalent bonding models
- Not all electrons in an atom participate in bonding. Those that do are called valence electrons
- Certain arrangements of electrons are more stable than others, as is explained by the octet rule
an electron in the outer-most electron shell of a representative or noble-gas element
Valence electron
The number of valence electrons in an atom of a representative element can be determined from the atom’s what
electron configuration
the chemical symbol of an element surrounded by dots equal in number to the number of valence electrons present in atoms of the element
Lewis symbol
The General Practice in writing lewis symbol
The general practice in writing these symbols is to place the first four dots separately on the four sides of the chemical symbol and then begin pairing the dots are further dots are added
Lewis Symbol: Three things to note:
- Representative elements in the same group of the periodic table have the same number valence electrons
- The number of valence electrons for the representative elements is the same as the Roman numeral periodic-table group number
- The maximum number of valence electrons for any element is eight
produced as a result of ionic bonding
Ions
an atom (or group of atoms) that is electrically charged as a result of the loss or gain of electrons
An ion
If an atom gains one or more electrons, it becomes
a negatively charged
if an atom loses one or more electrons, it becomes
a positively charged
Loss of one, two, or three electrons gives ions
with +1, +2, or +3 charges, respectively
Gain of one, two, or three electrons gives ions
with -1, -2, or -3 charges, respectively
This kind of atom is containing one, two, or three valence electrons
(Groups IA, IIA, and IIIA) tend to lose electrons to acquire a noble gas electron configuration
Metal Atoms
Group IA metals form how many ions
1+ ions