Chemical Bonds Ionic and Covalent Bonds

Chemical Bonds

1.Chemical bonds are what holds atoms together. 2.A chemical bond is an attraction between atoms that allows the formation of a chemical substance. 3.The electrons that participate in a chemical bond are called valence electrons. These are the electrons that are found in an atoms outermost shell. 4.Two types of chemical bonds that can be formed between atoms are ionic bonds and covalent bonds.

Ionic Bonds 5.An ion is an atom or group of atoms that has an electric charge. 6.When an atom loses an electron, it loses a negative charge and becomes a positive ion (cation) 7.When an atom gains an electron, it gains a negative charge and becomes a negative ion (anion) Grumpy Cat doesn’t want to be positive! Hhmmpphh!

Ionic Bonds(cont.)

8.An ionic bond is formed when one of the atoms loses its electron to another atom. It is the attraction between oppositely charged ions. 9. Positive and negative attract and the result is an ionic bond. 10.Ionic bonds occur between metals and nonmetals, when metals in Groups 1 & 2 gives away their VE to nonmetals.

Ionic Bonds(cont.) 11.For example, a sodium atom (which is a metal) reacts with a chlorine (a nonmetal) atom by losing its one valence electron to chlorine. 12.The sodium atom becomes a positive ion (Na+). 13. The oppositely charge ions attract each other forming the compound, sodium chloride (NaCl), or better known as table salt. The chlorine atom becomes a negative ion (Cl-).

Covalent Bonds

14. When two atoms come together they sometimes stick together to form a molecule. One way they can stick together is by covalent bonding. 15. In covalent bonding, the atoms are unstable because their outer rings of electrons aren't filled up. By sharing electrons with other atoms, these atoms can fill up their outer rings and become stable.

16. For example, let’s look at water. The oxygen atom needs two or more electrons to be stable, and the hydrogen atoms each need one. 17.When they get together, the oxygen atom shares one electron with each of the hydrogen atoms, and the hydrogen atoms each share one electron with the oxygen atom. Forming the compound, hydrogen oxide (H 2 O),or better known as water. Covalent Bonds (cont.)

19.Covalent Bonding occurs between nonmetal and nonmetals. e Sharing electrons is Caring 18.Now that the atoms have become stable, it's pretty hard to knock them back into being unstable again, so covalent bonds are strong and atoms that form with covalent (sharing) bonds are strong atoms. Covalent Bonds (cont.)

Add the following in your notes 20.A Covalent Bond where the sharing of the electron pair is unequal. Polar Covalent Bond 21. A Covalent Bond where the sharing of the electron pair is equal. Non-Polar Covalent Bond