Introduction to Chemical Bonding

Most of the matter you use every day is in the form of compounds and mixtures, not pure elements.All compounds are made of combinations of elements on the periodic table that chemically combine. The number of different compounds that exist is mind boggling!In this unit, we will learn why and how atoms of elements form compounds, but first, let's look at the basics. Distinguishing the difference between molecules and compounds. Referring to the concept map above, fill in each blank with the word "molecules" or the word "compounds".Spelling counts, do not hit space bar, capitalize when appropriate. Molecules are formed when two or more atoms join together. An atom is the smallest unit of all matter that defines an element. In molecules, the atoms can be the same kind of element or different elements. Compounds are molecules that contain at least two different types of elements. Both compounds and molecules are combinations of atoms, but they are different kinds of combinations. All compounds are molecules, but not all molecules are compounds. Counting Atoms Great Combinations In the chart below, you will see various compounds and the everyday products they are found in.Read each molecule name and chemical formula.Use ALL LOWERCASE letters.Spelling counts.The first row has been done for you as an example. Molecule name Formula # atoms of 1st element 1st element name # atoms of 2nd element 2nd element name # atoms of 3rd element 3rd element name water H₂O 2 hydrogen 1 oxygen XXXX XXXX nitrous oxide (anesthesia) N₂O 2 nitrogen 1 oxygen XXXX XXXX sulfuric acid (fertilizer) H₂SO₄ 2 hydrogen 1 sulfur 4 oxygen methane (fuel) CH₄ 1 carbon 4 hydrogen XXXX XXXX glucose (bread) C₆H₁₂O₆ 6 carbon 12 hydrogen 6 oxygen Most solids, liquids and gases around you exist because of their ability to combine or chemically bond with other elements and make new substances called compounds.All compounds are created by chemical reactions in which atoms bond and often hang tightly to their new arrangement and are not easily split. In the following section, look at the atoms that combined to form compounds and match them to the formula that shows the makeup of the compound. HCl H₂O CO₂ P₂O₅ NH₃ H₂O₂ SiO₂ CaCO₃ When nonmetals chemically bond they do so by sharing electrons. This bond is called a covalent bond and the compound formed is called a covalent compound.When a metal and a nonmetal bond, the metal transfers one or more electrons to the nonmetal. This bond is called an ionic bond and the compound formed is called an ionic compound. Refer to the periodic table above and, decide whether each element in the following compounds are a metal or a nonmetal.If the compound has only nonmetals, add it to the covalent compound category.If the compound has a metal and a nonmetal, add it to the ionic compound category. Covalent Compound CO₂ H₂O SO₃ HCl CH₄ Ionic Compound CaCl₂ NaF LiBr MgO FeCl₃ K₂O NaCl