The activity above helped you to think your prior knowledge on lesson 1 and lesson 2. It is easy right? Well, it is important to note that elements are single substance. You can easily see them in the periodic table. In the list above, iron is an element because it is a single substance with one atom and is present in the periodic table. Sodium chloride is a compound because it is a combination of two elements namely sodium and chlorine with 2 or more atoms. Therefore, an element cannot be broken anymore while compound it can be broken to its constituent elements.

Q1. Which among the substances are elements?

Q2.Which among the substances are compounds?

Q3. What are your bases of classifying them?​