Covalent bonds: are bonds in which one or more pairs of electrons are shared by two atoms.
Ionic bonds: bonds that one or more electrons from one atom are removed and attached to another atom that makes it positive and negative ions which attract each other.
Metallic bonds: Attractive forces between molecules in a liquid that can be characterized as Waals bonds.
2) What are some of the characteristics of each bond?
Ionic Bonding: the positive sodium ion and the negative chloride ion are strongly attracted to each other. This attraction which holds the ions close together is a type of chemical bond called an ionic bond. This means that An Ionic Bond is a chemical bond resulting from the TRANSFER of electrons from one bonding atom to another. It is formed when a cation transfers electrons to an anion. Some characteristics of the ionic bond are
· Crystalline solids at room temperatures
· Have higher melting points and boiling points compared to covalent compounds
· Conduct electrical current in molten or solution state but not in the solid state
· Polar bonds
Metallic Bonding- Pooling: In a metal the electrons of the outer energy levels are not held tightly to individual atoms. Instead, they move freely among all the ions in the atom forming a shared pool of electrons. Metallic bonds form when metal atoms share their pooled electrons. This bonding affects the properties of metals. For example when a metal is hammered into sheets or drawn into a wire, it does not break. Instead, layers of atoms slide over one another. The pooled electrons tend to hold the atoms together. Metallic bonding also is the reason that metals conduct electricity well. The outer electrons in metal atoms readily move from one atom to the next to transmit current.
Covalent Bonding: atoms of many elements become more stable by sharing electrons. Shared electrons are attracted to the nuclei of both atoms. They move back and forth between the outer energy levels of each atom in the covalent bond. So each atom has a stable outer energy level some of the time. Covalently bonded compounds are called molecular compounds. The atoms on a covalent bond form a neutral particle, which contains the same numbers of positive and negative charges. This is called a molecule, which is the basic unit of a molecular compound.
3) What holds a bond together?
The atoms are held together by opposite charges. They hold the bonds together because, since the electrons are given to the main atom, the separate atoms become ions and have a charge. And that is the charge that holds them together.
4) What are some examples of compounds representing the three bonds?
A Compound consists of two or more different Elements chemically combined to form a completely new substance having entirely different properties to those of the Elements of its make-up. Compounds can contain two elements that can either have ionic or covalent bonding. If we asked to classify them, you would see that if a compound is made from a metal and a non-metal, its bonding will be ionic. It occurs when one atom gains a valence electron from a different atom, forming a negative ion and a positive ion, respectively. These oppositely charged ions are attracted to each other, forming an ionic bond. And if a compound is made from two non-metals, its bonding will be covalent that means that it results when two atoms "share" valence electrons between them. The metallic bonding usually occurs with metals, such as copper.
5) What are some ideas that are necessary to be learned before learning to bond?
Atoms tend to lose or gain electrons in order to have a full valence shell and the stability a full valence shell imparts. The electrons are negatively charged, and an atom becomes positively or negatively charged while it loses or gains an electron.
The periodic trends, tells us the configuration of valence electrons. We can notice that as we move down the rows of the periodic table, all the elements have the same valence configuration of their outermost shell. We can also notice that as we move across the periodic table from left to right, the number of valence electrons increase in number, meaning that each time you move from period the elements are one step closer to have a complete outermost shell.
Sources:
http://wiki.answers.com/Q/Is_calcium_oxide_a_ionic_or_covalent_bond
http://dl.clackamas.edu/ch104-10/%286%29ionic.htm
http://chestofbooks.com/crafts/metal/Metal-Worker-Assistant/Metallic-Oxides.html
http://www.visionlearning.com/library/module_viewer.php?mid=55
http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/bond.html
http://www.chem1.com/acad/webtext/chembond/
Glencoe Science, Introduction To Physical Sciences Textbook
