<p> Chemical Bonds (Ionic)</p><p>I. Kinds of Bonds: A. Three types of chemical bonds you need to know 1. Ionic Bonds 2. Covalent Bonds 3. Metallic Bonds – Next Unit</p><p>A. Ionic Bonds: is the force of attraction between the opposite charges of the ions in an ionic compound</p><p>1. What is an ion and an ionic compound? a. Ion – Positively or negatively charged atom b. Ionic Compound – compounds made up of 2 or more ions</p><p> c. How does an atom become an ion? - An atom is considered electrically neutral if it has the same number of electrons as protons. If for any reason the atom loses or gains electrons the atom will have a charge because the negative charge of the electrons will be different than the positive charge of the protons</p><p>- Example: Magnesium 12 electrons and 12 protons (+ 12 protons) + (– 12 electrons) = 0 or No Charge</p><p>If magnesium gained 2 electrons then: (+12 protons) + (-14 electrons) = -2 or – Charge</p><p> d. How does an ionic bond form: - an ionic bond forms when oppositely charged atoms combine and there is a transfer of electrons</p><p>- Example NaCl: - Na has one electron in its valence shell and wants to get rid of it - Cl has 7 valence electrons and needs one - By Na transferring its one electron to Cl, - Na now has a complete valence shell; and by Cl gaining one it also has a complete shell.</p><p>- Ionic compound/bonds generally form between a metal and non-metal.</p><p>Chemical Bonds (Covalent Bonds and Polar and Non-Polar Molecules)</p><p>A. Covelant Bonds: 1. Definition: The attraction that forms between atoms when they share electrons, rather than losing or gaining electrons</p><p>2. Most atoms become stable by sharing electrons</p><p> a. Example: Cl2 Is this ionic or covalent, and how can you tell? - Answer: Covalent because there is no charge</p><p>- Explanation: Each chlorine atom has 7 electrons in its valence shell meaning they each only need 1 electron to have a full set. However each chlorine atom can’t give up one. So instead they will share an electron to give each the full set of 8 electrons</p><p> b. Generally formed between non-metals, and non-metals and metalloids</p><p>B. Polar and Non-Polar Molecules 1. Atoms in molecules do not always share electrons equally a. Electrons shared in a molecule may be more attracted to one atom than the other - Example: HCl The chlorine atom has a stronger attraction for electrons than hydrogen atoms do. So this means the electrons will spend more time near the chlorine atom than the hydrogen atom.</p><p> b. The uneven sharing gives the atoms in the molecule a slight but opposite charge from one another - In terms of HCl the chlorine atom has a slight negative charge and the hydrogen a slight positive charge. </p><p>- When this occurs it is considered a Polar Molecule Defined: A molecule that has a positive end and a negative End c. What happens when the atoms in a molecule share evenly? - Example: N2 Neither nitrogen atom has a greater attraction for electrons so the electrons will be shared evenly</p><p>- This causes the molecule not to have oppositely charged ends</p><p>- When this occurs it is considered a Non-Polar Molecule Defined: A molecule that does not have oppositely charged ends</p>