Chemical and Physical Properties
By: Sophie Ruffini
Physical Properties
Physical Change
Chemical Properties
Chemical Change
Sings of a Chemical Change
Production of Odor
After an experiment, if a substance produces a different odor than it had before, it is a sign of a chemical reaction. An example of this is when an egg rots, it creates a horrible, foul smell.
Temperature Change
After an experiment, if a substance has a different temperature, it is a sign of a chemical reaction. During experiments, a chemical reaction might occur when a substance loses heat or gains heat. An example of this, is when you add baking soda to vinegar. The vinegar will lose heat causing it to decrease in temperature.
Permanent Change in Color
During an experiment, if two substances are mixed and the combined substance creates a new color and you observe that the color change is permanent, it is a sign of a chemical reaction. An example is if you mix Iodine with flour there will be a permanent color change of purple!
Forms Gas
After an experiment, if you notice bubbles, you have gas. If a substance is bubbling, this is a sign that gases are being released. An example of this is if you combine vinegar and baking soda, gas will be released causing the vinegar to bubble.
Precipitate
During an experiment, when you mix two liquids and you see a solid form, it is a sign of a chemical reaction. When you mix two liquids and it forms a solid that won't dissolve, the solid is called a precipitate. An example of this is if you combine AgNO3 and NaCl it will make a precipitate!
Energy Release
After an experiment, if you notice the is substance producing sound, heat, or light, it is a sign of a chemical reaction. An example of this is when you light a match, it will produce fire. This fire will then produce light and heat.
Essential Question
It is important for people to understand physical properties because we use/make these observations all the time. That chair is blue, the floor is green, the pillow is soft, that speaker is loud, etc. We need to understand this, so we are able to fully recognize our world and be able to experience all it has to offer.
It is important for people to understand physical changes because we use them all the time! As humans, we like to experiment with food. We can do this by freezing some of our favorite foods. By freezing the food, we have just created a physical change. This circle just goes on. If we want to make pasta, we have to boil the water. That's a physical change! We need to understand this because we experience physical changes all the time to do simple tasks such as cook meals!
It is important for people to understand chemical properties, so we can avoid things that are toxic that will hurt us. Plus, this will also let us know when something is flammable, like hair spray. This will warn us to keep the flammable objects away from fire. Also, it will warn us when something is corrosive and will damage our skin. Being able to understand chemical properties will be able to save us from some very unpleasant situations.
Lastly, it is important for people to understand chemical changes because chemical changes are essential for us to be able to do many things. To be able to make many foods, we need to make substances such as cake mix. Cake mix is a chemical change because we have to add many different substances to make one substance. Once we make cake mix, we can not separate the ingredients out once again. As many people probably don't know, cake mix is a chemical change. Plus, as our world evolves around us, there are many chemical changes happening, like your old car rusting or your mother's favorite vase tarnishing. By being able to understand chemical changes, we are able to understand how our world works around us.