NATS 1840 Chapter 3: 3.5-The Law of Conversation of Matter
8 Feb 2019
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Document Summary
Difference between a physical and a chemical change. Matter can change from one physical form to another or change its chemical composition. Physical change : chemical composition is not changed. Chemical change : aka chemical reaction, there is a change in the chemical composition of elements or compounds. Only atoms and molecules undergo chemical reactions. 1) nuclei are conserved, so the # of atoms of each element remains the same through the reaction. 2) the total charge remains the same through reaction. When a physical or chemical change occurs, no atoms are created or destroyed. The atoms are rearranged into different spatial patterns (physical) or different combinations (chemical) No away : everything we think we have thrown away is still here somewhere on the planet in one form or another. Material resources are limited (so many atoms of iron) The law of conservation tells us that we will always produce some pollutants, but we can produce less.
