Exploring 2 Types of Bonds Science 10 Chemistry Unit

There are 2 types of bonds: 1.Ionic bonds 2.Covalent (or molecular) bonds

Ionic Bonds Ionic bonds are formed when one or more electrons are transferred from one atom to another atom. Ionic bonds are formed when one or more electrons are transferred from one atom to another atom. This produces positively This produces positively and negatively charged particles called ions.

The forces of attraction that bind oppositely charged ions together are called ionic bonds. The forces of attraction that bind oppositely charged ions together are called ionic bonds. Ionic bonds generally occur between metals and nonmetals ( cations and anions ). Ionic bonds generally occur between metals and nonmetals ( cations and anions ). Anions and cations are held together in an ionic bond due to electrostatic forces --- oppositely charged “ force fields ” resulting from the oppositely charged ions. Anions and cations are held together in an ionic bond due to electrostatic forces --- oppositely charged “ force fields ” resulting from the oppositely charged ions.

Examples: 1.NaCl 2.Fe 2 O 3 3.BaF 2

Covalent Bonding: Involves the “ sharing ” of electrons. Involves the “ sharing ” of electrons. It involves the bonds formed between a non- metal and a non-metal (or metalloid). It involves the bonds formed between a non- metal and a non-metal (or metalloid).

Important: Since these bonding non-metals (or metalloids) wish to gain electrons to become like a noble gas, and they can’t gain electrons from each other at the same time, they must share their electrons so they can both become like a noble gas. Since these bonding non-metals (or metalloids) wish to gain electrons to become like a noble gas, and they can’t gain electrons from each other at the same time, they must share their electrons so they can both become like a noble gas. These compounds or molecules that are formed are neutral …they have no charge. These compounds or molecules that are formed are neutral …they have no charge.

Examples 1.H 2 O (water) 2.CO 2 (carbon dioxide) 3.O 2 (oxygen)

Nomenclature: Different classes of compounds have different rules for naming. Different classes of compounds have different rules for naming. Before naming a compound, it is important to check which class it belongs to so that you will use the appropriate set of rules. Before naming a compound, it is important to check which class it belongs to so that you will use the appropriate set of rules.

Rules for Naming Binary Molecular Compounds To use this set of rules, the compound must be a molecular or covalent compound. To use this set of rules, the compound must be a molecular or covalent compound. In other words, it must be a non-metal + a non-metal (or metalloid) compound In other words, it must be a non-metal + a non-metal (or metalloid) compound

Rules: Name the first element as the name you see on your periodic table. Name the first element as the name you see on your periodic table. Name the second element as you see it in your “Periodic Table of Ions”…the 2nd element always ends in “- ide ” Name the second element as you see it in your “Periodic Table of Ions”…the 2nd element always ends in “- ide ” Use numerical prefixes to show how many of each atom is present in the molecule. Use numerical prefixes to show how many of each atom is present in the molecule. Mono- is frequently or often, omitted. Mono- is frequently or often, omitted. Write these on the “file cards” then place them in your plastic sheath. Write these on the “file cards” then place them in your plastic sheath.

Prefix Number of Atoms in Compound Mono-1 Di-2 Tri-3 Tetra-4 Penta-5 Hexa-6 Hepta-7 Octa-8 Nona-9 Deca-10

Naming Binary Molecular Compounds Write the names of the following covalent compounds : 1.SO 3 _______________________________________ 2.N 2 S _______________________________________ 3.PH 3 _______________________________________ 4.BF 3 _______________________________________ 5.P 2 Br 4 ______________________________________ 6.CO ________________________________________ 7.SiO 2 _______________________________________ 8.SF 6 _______________________________________ 9.NH 3 _______________________________________ 10.NO 2 ________________________________________ Sulphur trioxide Diphosphorous tetrabromide Carbon monoxide silicon dioxide Sulphur hexafluoride Nitrogen trihydride or Ammonia nitrogen dioxide Dinitrogen monosulfide Phosphorous trihydride Boron trifluoride

Formula Writing of Binary Molecular Compounds 1.nitrogen trichloride ________________________ 2.boron monocarbide __________________________ 3.dinitrogen trioxide ________________________ 4.phosphorus pentafluoride __________________ 5.methane ______________________________ 6.sulfur dibromide _________________________ 7.diboron tetrahydride ______________________ 8.oxygen difluoride _________________________ 9.carbon disulfide __________________________ NCl 3 CS 2 N2O3N2O3 PF 5 CH 4 SBr 2 B2H4B2H4 OF 2 BC