So at this point we know that conversion factors tied together two different units, and we're going to say that the most common conversion factors deal with units involved in length, volume and mass. Now we can see that there's a lot of conversion factors being listed here. And remember, Onley, the ones that are in purple boxes are ones that you should commit to memory and memorize. All the other ones are usually given to you in some way or another, either within the question or as a formula sheet. So consult with your professor to make sure which one of these you need to know for the upcoming exam or quiz or homework. Okay, the ones in purple, though you should always at least Novo's all right. So when it comes to a length, the conversion factors and the first one we need to memorize one inch is equal to 2.54 centimeters. Next, we can say that 1 m is equal to 1.94 yards. One yard is equal to 3 ft. One mile is equal to 5280 ft, and then finally, one kilometer is equal 2. miles. So these are our most common types of conversion factors dealing with length. Next, we have volume out of this. The one that you should always remember is one millimeter is equal toe, one centimeters cube. Then we're going to say here that one leader is equal toe. One decile meters cube. One leader is equal to 1.57 quarts, and one gallon is equal to 3. leaders finally mass for mass, we can say one out is equal to 28.35 g. 1 kg is £2.205 and finally we have £1 is equal to 453.59 g. Oftentimes, professors will just round this upto g for the number of pat for equal to £1. So again, as we can see, there's many different conversion factors. These are the most commonly seen ones within chemistry, and out of all of these, the one you should always memorize for sure are the two that are in the purple boxes. The other one's consult with your professor to make sure if you have to memorize them, or will they be given to you on your upcoming quizzes or exams? All right, now that we've seen these common types of conversion factors, let's move on to the next question.