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In the videos above they each give a basic definition of chemistry. Both say that chemistry is the study of matter. They also say that chemistry is disassembling something until it cannot be broken down further. Once you have the basic parts, or elements, you can make something completely new and different from the original. The videos both state that there are only two things in the universe, matter and energy. There are three different kinds of matter, solids, liquids and gases, and energy cannot be created nor destroyed according to The Law of Conservation of Energy. The third video describes the composition of matter and states that all matter is made up of elements which cannot be broken down further. Elements also have unique physical properties, properties that we can see, and chemical properties, properties or behaviors of a substance when it undergoes a chemical change or reaction.
Contrast
The first video defines chemistry as "the study of matter and energy and the interactions between them." The second video defines chemistry as "the study of the composition and properties of matter and the changes it undergoes". The first video spends the majority of it's time focusing on this and relating it to legos and things that are easy to disassemble. However the second video branches off to explain practical, real world uses for chemistry. These are making medicine, developing new types of fuels and "solving the mysteries of the universe". The narrator of the second, more in-depth video continues to elaborate and explain the basics of chemistry in a way that starts with the simple need to knows and builds upon that.
In the videos above they each give a basic definition of chemistry. Both say that chemistry is the study of matter. They also say that chemistry is disassembling something until it cannot be broken down further. Once you have the basic parts, or elements, you can make something completely new and different from the original. The videos both state that there are only two things in the universe, matter and energy. There are three different kinds of matter, solids, liquids and gases, and energy cannot be created nor destroyed according to The Law of Conservation of Energy. The third video describes the composition of matter and states that all matter is made up of elements which cannot be broken down further. Elements also have unique physical properties, properties that we can see, and chemical properties, properties or behaviors of a substance when it undergoes a chemical change or reaction.
Contrast
The first video defines chemistry as "the study of matter and energy and the interactions between them." The second video defines chemistry as "the study of the composition and properties of matter and the changes it undergoes". The first video spends the majority of it's time focusing on this and relating it to legos and things that are easy to disassemble. However the second video branches off to explain practical, real world uses for chemistry. These are making medicine, developing new types of fuels and "solving the mysteries of the universe". The narrator of the second, more in-depth video continues to elaborate and explain the basics of chemistry in a way that starts with the simple need to knows and builds upon that.