CHEM 120 Week 3 Exam 1 (Units 1 and 2)

Answer the following questions (1 point each) to add up to 5 points back to your exam score. 1. Question: Choose any isotope of an element and answer the following a. Write the isotopic formula b. How many neutrons in the isotope? c. How many protons are in the isotope? d. How many electrons are in the isotope? e. What is the mass number for the isotope? 2. Question: Choose any molecular compound with 3 to 5 atoms in it. a. Draw the Lewis structure. b. Give step by step directions for how to draw the Lewis Structure. c. Give the molecular shape d. Give an explanation for how you determined the shape e. Is your molecule polar or nonpolar 3. Question: Explain what hydrogen bonding is. a. Give an example of a molecule that would hydrogen bond b. Explain how hydrogen bonding affects physical properties like boiling point. 4. Question: Explain the difference between ionic and molecular (covalent) bonding. Make sure you include what happens with the electrons. a. Give an example of an ionic compound, give the correct formula and correct name. Explain how you determined the name of the compound from the formula b. Give an example of a molecular compound, give the correct formula and correct name. Explain how your determined the name from the formula. 5. Question: Explain what a negative control is in an experiment. a. Give an example of an experiment and the negative control b. Identify the independent and dependent variables