STUDENT NAMES IN GROUP___________________________________________________________________________ Period_________ GUIDED INQUIRY 1.Examine the four models below. What substances are represented? (1)_________________________________ (2)____________________________ (3)_______________________________ (4) ________________________________ (2) Oxygen = O 2 (4) Carbon dioxide = CO 2 (1) Water = H 2 O (3) Nitrogen = N 2 2.What are the chemical symbols for the four substances? (1)_____________ (2)____________ (3)_____________ (4)_____________ 3. Do you think the colors might have a meaning? If so, complete the sentence below about the color red. In these models, the color red means _____________________________________________________________________. 4.In the models, each sphere represents an atom. Complete the chart below by looking at the models. 5.Study the chart you just made above. How are substances #2 and #3 different from #1 and #4? ______________________________________________________________________________________________________ ______________________________________________________________________________________________________. Name of Substance Number of Atoms Number of Different Colors 1._____________________________ ___________ ___________ 2._____________________________ ___________ ___________ 3._____________________________ ___________ ___________ 4._____________________________ ___________ ___________

6.ELEMENTS are made of only one type of atom, the smallest part into which a substance may be divided. Based on the models, which substances do you think are ELEMENTS? _______________________________________________________________________________________________ 7.COMPOUNDS are made of two or more different elements. Based on the models, which substances do you think are COMPOUNDS? ___________________________________________________________________________________________________________ 8.What do you think the numbers mean on the models? ______________________________________________________________ __________________________________________________________________________________________________________ 9.The EASY way to know if a substance is an ELEMENT or COMPOUND has to do with capitalized letters in the chemical symbol. Study the chemical symbols of the substances, then WRITE A RULE explaining how to know the difference between an element and a compound. ___________________________________________________________________________________________________________ 10.Look at the model below. Based on its color and number of spheres, what do you think it is? The model represents an ___________________ of ___________________. BONUS: List which ELEMENT each color represents in the models. RED = _______________________ BLACK = _______________________ BLUE = _______________________ GREEN = _______________________

Using the RULE you wrote for identifying elements and compounds, label the following as either element (E) or compound (C): NaHCO 3 ________ F ______ C 12 H 22 O 11 ______ Al ______SiO 2 ______ SiO 2 ______ Fe ______ Sn ______ NaCl ______ CaCo 3 ______ He ______ B ______ C ______Cu ______ Ag ______ MgSO 4 ______S ______ NOW, rewrite your RULE (if needed): ____________________________________________________ ______________________________________________________________________________

Chemical Name of Substance Formula Element or Compound? Elements found in the common substance NaHCO 3 Al Fe C MgSO 4 S NaCl SiO 2 Sn He Cu Ag CaCo3 EXTENSION: Go to stations to identify these common substances by their chemical formulas. Determine if they are elements or compounds. Identify which elements make up each substance. (Hint: Ignore the numbers.)