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Using Chemistry Language

Using Chemistry Language.

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Using Chemistry Language

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  1. Using Chemistry Language

  2. Chemist use an international chemical language to represent, compounds, molecules, and elements. This language is written as chemical symbols, formulas and equations. The “letters” used in this language represent one atom of the element. These symbols usually come from the place where these atoms were found, the scientist who discovered them, or from other languages such as Greek or Latin. • The symbols are found on the periodic table of elements. • The first letter is capitalized and the second letter, if necessary, is lowercase. • Each capital letter represents a different element.

  3. Find the card labeled “symbols” in your card set, and then find the definition for this word. Put the two cards side-by-side on your vocabulary template. Now look through the colored set of cards and find either an example or a diagram of the definition.

  4. Atoms can be combined to form chemical bonds creating new substances. The bonds are represented by symbols for the atoms that make up the substance and may or may not include a number to show how many atoms of each element are present. These symbols and numbers form a chemical formula. An example of a chemical formula is NaCl. This is the chemical formula for sodium chloride (table salt).

  5. Find the card labeled “chemical formula” along with its definition and examples • KOH –Potassium Hydroxide • H3PO4 -Phosphoric Acid • CH3COOH—Acetic Acid (Vinegar) • The molecular chemical formula for glucose is C6H12O6, • sucrose is Cl12H22O6 • and octane is C8H18

  6. In order to make it easier to describe elements and molecules, chemical formulas are used. For example, H represents one atom of hydrogen and "O" represents one atom of oxygen. If we want to represent two atoms of hydrogen, instead of writing H H, we write H2. The subscript "2" means that two atoms of the element hydrogen have joined together to form a molecule. A subscript is only used when more than one atom is being represented. The graphic below illustrates the formula for water using symbolsFind the card labeled “subscript”, its definition, and the card with subscripts underlined on it.Glue all cards on your template

  7. Chemical Reactions • Sulphuric acid and copper oxide ---> copper sulphate and waterH2SO4 + CuO ---> CuSO4 + H2O • Bromoethane and sodium hydroxide ---> ethanol and sodium bromide • CH3CH2Br + NaOH ---> CH3CH2OH + NaBr • A + B → AB • 2 H2 + O2 → 2 H2O • Find the “chemical reaction” card along with its definition. Then find the colored card with examples of these reactions. Chemical reactions involve the forming and breaking of chemical bonds, causing atoms to be rearranged into new substances. The new substances will have different chemical and physical properties than the original substances.

  8. Chemical changes happen when new substances are formed.Chemical change can occur in more than one way. • Appearance of bubbles • Formation of a precipitate • Temperature change • Color change

  9. Chemical Equation A chemical equation describes what happens in a chemical reaction. The equation identifies the starting materials and resulting substances, the formulas of the participants, and the amount of each substance. Find the card labeled “chemical equation”, its definition and examples. An example of a chemical equation for the formation of water is: 2H 2 + O 2 → 2H 2 O Na2CO3 + HCl   -->   CO2 + H2O + NaCl • A chemical equation is a symbolic representation of a chemical reaction.

  10. One molecule of methane will react with two molecules of oxygen gas and yield one molecule of carbon dioxide gas plus two molecules of water. This is how chemical equations would have to be written out every time a reaction takes place if scientists did not used the international chemistry language of symbols, formulas, and equations. Here is the equation written again using chemistry shorthand: CH4 + 2O2 → CO2 + 2H20 Which version of the equation is easier to write?

  11. A regular sized number in front of any chemical formula in achemical equation represents the number of molecules involved in that reaction. An example of coefficients in an equation is: 2Na+ Cl2→2NaCl. As is the case with subscripts, no number infront of a chemical formula indicates (means) that there is only 1 of those molecules involved in the chemical reaction.

  12. The Law of Conservation of Mass states that in a chemical reaction there is no loss of mass. Each type of element will have the same amount before the reaction and after the reaction, or as reactants and products. But you can't change the materials that participate in the reaction, so you must write an integer coefficient in front of (to the left of) each material in the reaction to make sure every type of atom has the same number on each side of the reaction.

  13. There are 2 parts to a chemical equation: REACTANT PRODUCT In a chemical equation, the formulas written on the right side of the arrow (→) are the new substances being formed and are called products. A plus sign (+) between them indicates that there is more than one new substance being produced in the reaction. Find the card labeled “product” and its definition. • In a chemical equation, the formulas written on the left side of the arrow (→) are the starting substances and are called the reactants. A plus sign (+) between them indicates that there is more than one substance reacting in the reaction. Find the “reactant” card in your card set, and then find the definition for this word

  14. Reactants are formulas written on the left side of the arrow symbol (→). They are the starting substances in a chemical reaction. • Products are formulas written on the right side of the arrow symbol (→). They are the new substances formed in a chemical reaction.

  15. Your sheet should look like this when all your cards have been glued on properly.

  16. The arrow symbol (→) shows that a reaction has taken place. The arrow is read as “yields” or produces. Basically the arrow in a chemical equation is the same as an equal sign in a math equation • In a chemical equation, elements and compounds may be displayed. In Unit 2, you learned that an element is one kind of atom. • Find the “yields” card along with its definition and glue on any cards that have not been glued.

  17. Hydrogen atoms A compound is a substance composed of two or more elements chemical combined and in a definite proportion. For example, each water molecule will always have two hydrogen atoms and one oxygen atom. Oxygen atom

  18. Precipitate When a solid forms from the mixing of two liquid solutions

  19. EndothermicReaction A reaction that absorbs heat which causes the product to become colder

  20. Exothermic Reaction A reaction that releases heat (becomes warmer)

  21. Diatomicmolecules • O 2 • H 2 • N 2 • F 2 • Cl 2 • I 2 • Br 2 Atoms that share electrons and complete their valence electrons

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