Which procedure did early chemists use to determine which substances were elements? a. they observed the substances that made up individual atoms. b. they physically broke down the elements they discovered. c. they broke down materials by chemical means. d. they observed the way the materials looked.

Put these processes of the water cycle in the correct order, starting at the point where the water is in the lake: 1. water evaporates into the atmosphere 2. rain, snow, or other precipitation falls 3. water collects into larger bodies of water 4. water vapor condenses into liquid water

For the following dehydrohalogenation (e2) reaction, draw the zaitsev product(s) resulting from elimination involving c3–c4 (i.e., the carbon atoms depicted with stereobonds). show the product stereochemistry clearly. if there is more than one organic product, both products may be drawn in the same box. ignore elimination involving c3 or c4 and any carbon atom other than c4 or c3.

Each of the following reactions is allowed to come to equilibrium and then the volume is changed as indicated. predict the effect (shift right, shift left, or no effect) of the indicated volume change. drag the appropriate items to their respective bins.co(g) + h2o(g) < => co2(g) + h2(g) (volume is decreased) pcl3(g) + cl2(g) < => pcl5(g) (volume is increased) caco3(s)< => cao(s) + co2(g) (volume is increased)