Students are learning to balance equations. Today they learned that reactants are what you start with and are on the left side of the equation. Products are on the right side of the arrow and are what is made by process of a chemical change.
Because of the Law of Conservation of Mass, the number of atoms have to be equal on both sides. To balance an equation, the coefficients are changed. Coefficients are the big numbers in front that tell you how many molecules there are. The subscripts (the little lower numbers) are not allowed to be changed because those are there to make neutrally bonded molecules (what we learned in the last unit.
By changing the coefficients and counting the number of atoms on both sides of the arrow, balancing can be achieved.
If you were absent for the Physical versus Chemical lab, you can make up the majority of it by following the link below and watching YouTube videos of the experiments. You can also just check them out because they are cool.
Open a link in a new tab. In the blue box, look for "Play Games" and "Scatter." You will then need to drag the names to the correct formula. If it disappears, you matched it correctly. Play each set a couple of times until you get really good. You can also use these as flashcards and make up and take tests.
Click on the rice above to test your knowledge of the Periodic Table while earning rice for the United Nations World Food Program. You can also test your knowledge of vocabulary as an excellent SAT prep.