In the first lesson of Chapter 14, students were introduced to the concept of LD50 (the dose of a compound that is lethal to 50% of the population).  Students considered the ChemCatalyst in slide 3 of the Lesson 74 PowerPoint, and also recorded the LD50 definition on slide 6.  Students then received both the Lesson 74 Worksheet and accompanying Lethal Doses Handout to work on during class.  For homework, students were assigned Lesson 74 textbook questions 4 and 5.  Example LD50 calculations from the whiteboard are pictured below: