This section is about the three types of Chemical Bonds: But 1 st lets review some facts about atomsandthe periodic table.

Lets review some past facts about atoms. 2. The nucleus has positive protons 1. The center of the atom is known as the nucleus. + and neutral neutrons. N N N N N N F94F Around the nucleus are orbits that negative electrons travel on Now when we diagram atoms we will summarize the subatomic particles. Instead of this model We will use this model P = 4 N = 5 4 P = 4 E (0 charge)

Nonmetals 9 F Example: Fluorine Round to one’s place are neutrons 9 F 19 F 1. Fluorine is in the nonmetal section. Row 2 Column Row 2 means 2 orbits. 3. Family 17 means 7 valence electrons. N Now for the nucleus. N + N + N N N + N N + N + NN 9 are protons 19 items in the nucleus. P = 9 N = 10 - N P = 4 E (0 charge) N - N - N - N -

What is chemical bonding? The combining of atoms of elements to form a new substance. H O Hydrogen (a gas) Oxygen (a gas) + + Becomes Water molecule

To stabilize their orbits! Why would atoms want to bond? Some atoms have 1, 2, or 3 electrons in their last energy level. Huh! P = 4 N = 5 N - N - Be - N - These atoms will release these electrons and drop the last level. Meanwhile, some atoms are trying to fill their last orbit by gaining 3,2 or 1 e-. P = 8 N = N - N - Oxygen - N - It’s all about the valence electrons. + -

1. Forms between a metal atom and a nonmetal atom. 3. Atoms from the periodic table start off neutral. This is because the # of positive protons = the # of negative electrons. P = 3 N = 4 Li Lets look at the metal atom Lithium and the nonmetal atom Fluorine. P = 9 N = 10 F metals nonmetals 3 P = 3 E9 P = 9 E 4. These atoms wont stay neutral for long. 5. Atoms want a full orbit, so Li & F each have a choice. P = 3 N = 4 Li P = 10 E P = 3 N = 4 Li P = 2 E P = 9 N = 10 F P = 10 E P = 9 N = 10 F P = 2 E 6. For Li, will it add 7 e-’s to the last orbit? or * Notice that this would create a negative atom (anion) because the electrons would out number the protons by or 7. Will Li drop the last orbit & e-. * Notice that this would create a positive atom (cation) because the protons would out number the electrons by If you said lose e-’s, you were correct! 8. For F, will it gain 1 e- to the last orbit? or 9. Will F drop the last orbit & 7 e-’s. If you said gain 1 e-, you were correct!

Atoms with a few valence electrons have low ionization energy. Ionization energy is the energy needed to remove electrons. P = 3 N = 4 Li P = 9 N = 10 F P = 9 N = 10 F P = 3 N = 4 Li Li has low ionization energy. Atoms with a many valence electrons have high ionization energy. F has high ionization energy. + - A metal cation joining a nonmetal anion forms a salt.

Atoms with a few valence electrons have low electron affinity. Electron affinity is the ability to attract electrons. P = 3 N = 4 Li P = 9 N = 10 F Atoms with a many valence electrons have high electron affinity. Li has low electron affinity. F has high electron affinity. -

Form when a positive metal atom…….. P = 4 N = Be - * loses 1, 2 or 3 e-’s. * the atom to become a positive atom (cation) P > 2 E * Because the protons outnumber the electrons, attracts to a negative nonmetal atom Nonmetals P = 8 N = N - N - Oxygen 8 P < 10 E Positive and Negative Attract * gains 1, 2 or 3 e-’s. * the atom to become a negative atom (anion). *Because the electrons outnumber the protons, The metal atom will shift from neutral to positive when it ….. The nonmetal atom will shift from neutral to negative when it ….. P = 8 N = N - Oxygen - - -

Ionic Bond, A Sea of Electrons

This type of bond forms between nonmetal atoms Nonmetals P = 9 N = Fluorine - P = 9 N = Fluorine - The goal is to have a full outer level!! P = 9 N = Fluorine P = 9 N = Fluorine - - If it is two of the same element it is called diatomic. Atoms joined by a covalent bond (nonmetel to nonmetal form a compound).

Covalent Bonds Slide taken from:

Formed between atoms of metallic elements Electron cloud around atoms Good conductors at all states, lustrous, very high melting points Examples; Na, Fe, Al, Au, Co Slide taken from:

Metallic Bonds: Mellow dogs with plenty of bones to go around. Slide taken from:

There are two main groups in the periodic table. Non-metals Metals

+ + N N Scrap page Nonmetals No transparency transparency Nucleus To stabilize their orbits!