Dialogue between students and teachers

Teacher: good morning students
Student: good morning mother
Teacher: be it disciples, today we will learn about material classification, the first element, the element is pure substance which can not be described into other simpler substances with ordinary chemical reactions, the element is the basic ingredient of the material. The second is a compound, the compound is a pure substance that can decompose through ordinary chemical reactions to form other simple substances. The compound is a combination of two or more elements present in a material, produced by a chemical reaction. The latter is a mixture, a mixture is a material composed of two or more substances with an irregular composition and still possessing the properties of the original substance. The mixture can be classified into heterogeneous mixtures and homogeneous mixtures. Are the students of you who have not understood the material we are studying today?
Student: I am mother (while raising hands), what are the examples of elements, compounds, and mixtures. Can you explain it?
Teacher: Okay, so here goes. Examples of elements are metallic and nonmetallic elements. Examples of compounds are petroleum, carbohydrates, fats, proteins and many others. And the example of the mixture is a mixture of granulated sugar and salt, this mixture is a heterogeneous mixture, if a homogeneous mixture for example is a mixture of water, tea and sugar. Are the students obvious?
Student: already mother ..
Teacher: it's okay that students now give your mothers a job to look for in the sample book of logs and non-metals as well as samples of homogeneous and heterogeneous mixtures, then the ones who have finished please go ahead to read the results to the other friends.
After a few minutes.
Student: mother, I'm done ..
Teacher: all right, please go ahead to read it to friends
Student: okay, I'll read the results I get, examples of metal elements are aluminum, barium, iron, gold and many more. Examples of nonmetallic elements are sulfur, oxygen, nitrogen, carbon, helium and much more. Examples of homogeneous mixtures are alcohols, mouthwashes, detergents and others. Examples of heterogeneous mixtures are ice in soda, soil, cereals in milk and much more.
Teacher: well, your friend has already explained his examples, do you understand?
Student: already understand mother
Teacher: well, if you have understood, today's lesson mothers end. We continue next week, good morning ..
Student: good morning mother