Start by mentioning the contents that will be seen in each activity, so that the student gets a context and a logical framework for the development of said activities. Do you like soup? Can you imagine a soup without salt? It is possible that you have had to add some salt to a soup sometimes before; however, it is very likely that you have not thought about what happens with those little crystals when they make contact with the soup. Throughout this learning unit, we invite you to recognize some properties of the chemical elements that give flavor to a soup, sweeten a juice, and transmit information between neurons. Additionally, we will inquire about the negative effects produced by using a group of chemical elements known as heavy metals, which are part of different products, from cell phone batteries, to the toothpaste that you use daily.