Creating a Positive Learning Environment for Everyone Be respectful of your classmates Save conversation for clicker portions of lecture Put cell phones in “airplane” mode Turn off tablets Close laptops

Announcements Textbook homework and lab write-up due tomorrow in discussion Electronic HW #2 (Lon-Capa) Type 1 due Monday, 9/11, 7:00pm Type 2 due Wednesday, 9/13, 7:00pm Prelecture Assignments Lab write-ups must be your own. What to memorize for exam.

By the Exam… Know the polyatomic ions and charges (Table 5.4). Know common ions and symbols (Tables 5.1 and 5.2). The charges for these come from the periodic table. Know prefixes (Table 5.3).

Clicker #1 What is the average mass of one hydrogen atom? A) 1.008 amu B) 1.008 g C) 1.008 moles D) Both A and B are correct.

Clicker #2 How do these two numbers compare? A) # of H atoms are less than the # of C atoms B) # of H atoms are equal to the # of C atoms C) # of H atoms are greater than the # of C atoms D) I have no clue. Help!

Clicker #3 Which sample contains a greater number of atoms? 10.0 g Cu or 10.0 g Mg A) 10.0 g Cu B) 10.0 g Mg

Clicker #4 Which sample contains a greater number of atoms? 10.0 g Cu or 5.00 g Mg A) 10.0 g Cu B) 5.00 g Mg

Additional Question What is the number of atoms of hydrogen in 100.0 g magnesium hydroxide?

Closing Joke What do you have when you see a mole of moles digging a mole of holes? A bunch of molasses