By Avani S. 6F2


Hello. Today I will be talking to you about chemistry. More specifically, I will talk about the periodic table and chemical reactions.

What is Chemistry?

Chemistry is the scientific study of matter, its properties, and its interactions with other matter and energy. You might think that chemists are scientists in white lab coats, trying to mix different liquids together in a lab, but the truth is that all of us are chemists. For example, when your mother is cooking something at home, that is chemistry. In fact, chemistry can be anything, from taking a shower to launching a space shuttle. Chemistry is one of the physical sciences that helps us to discover and explain our world.

The Periodic Table

What is the Periodic Table?

The periodic table is like a big grid. It helps organize the chemical elements in order of their atomic number, which means the amount of protons in their nucleus (the centre of an atom). The rows are called “periods”, and the columns are called “groups”. The metals are on the left side of the table, the semimetals (metalloids) in the centre, and the nonmetals are on the right side. The periodic table has 10 colour-coded categories: alkali metal, alkali earth, transition metal, basic metal, semimetal, nonmetal, halogen, noble gas, lanthanide, and actinide. There are currently 118 discovered elements, 4 of which are unnamed.
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Chemical Reactions

What are Chemical Reactions?

Chemical reactions are when two or more molecules interact with each other and cause them to change. Bonds, or relationships between molecules, can be broken to form new ones with other molecules. For example, if you turn on a fan, it will cause the air to become cooler. However, there is no actual change in the air molecules. That is called a physical change. When you wash clothes, the detergent breaks up the molecules in your stains. That is a chemical change. There are 5 major types of chemical reactions: combination or synthesis, decomposition, combustion, substitution or single replacement, and metathesis or double displacement. Let's learn more about them.
Major Types of Chemical Reactions


Thank you for listening to my presentation. I hope you liked it!