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Three signs of a chemical reaction include the release or absorption of heat, a change in color, and the creation of a gas or a precipitate.
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How do you know if a chemical reactions has taken place?
Signs of chemical reactions may be: - Gas release - Formation of a precipitate - Change of color - Change of odor - Change of pH - Change of aspect - Change of viscosity - Change of the temperature - Visible formation of new compounds
How do you know that baking bread is a chemical change and not a physical change?
Its a chemical change because its changing what it is (from dough to bread)
Which change below is a chemical change?
dont know your out of luck
What type of change occurs at the molecular level?
We have already seen that chemical reactions are changes in matter and that they happen everywhere. If you look a little closer and observe your surroundings, you will notice that many of the substances around you are changing. Are all of these changes chemical reactions? No. You know that sometimes chemical changes take place and sometimes physical changes take place. For this reason it is said that A physical change is a change in the properties of a substance that does not change. A change of state is a physical change. A chemical change is a change in the properties of a substance. Combustion is a chemical change You can memorize these definitions, but do you know what we mean by "properties of matter"? When does it change and when does it not? If you can't answer these questions, you don't know how to distinguish between physical and chemical changes. Remember everything you know about the composition of matter, about elements and compounds, about pure substances and mixtures. When we talk about the properties of a substance, we describe its composition and structure, just as we describe what elements it is made of and in what proportions. Regardless of whether it is a single pure substance or a mixture of several substances. You already know that a pure substance is one whose composition is fixed because all the particles are the same, and can be expressed by a formula, such as H 2Or, the chemical formula for water, or NaCl, the chemical formula for sodium chloride, a table salt. When one or more of these pure substances "disappear" in a substance transformation, a chemical change or chemical reaction takes place. But as you know, substances do not disappear (Lavoisier's law). So, from the original atoms that "disappear", one or more new pure substances "emerge". If during the transformation no matter "appears" or "disappears", then a physical change has taken place.
Is a sausage cooking a chemical reaction?
don't know..... personally i think it is because it is a change and a change is a chemical reactions
How do you know when a chemical change has taken place when a firework goes off?
youwill hear it
How do you know if a chemical reactions has taken place?
Signs of chemical reactions may be: - Gas release - Formation of a precipitate - Change of color - Change of odor - Change of pH - Change of aspect - Change of viscosity - Change of the temperature - Visible formation of new compounds
How do you know a chemical change takes place when a log burns?
Burning is a chemical process: the nature of the initial material is changed.
What kind of changes has taken place when you sharpen a pencil how do you know?
It is a physical procedure because the chemical composition remain unchanged.
How do you know that chemical change took place in bread heat?
Because you cannot reverse the process, like you could a physical change.
A change in matter that produces new substances is called?
Chemical change. References: Intro to Matter book.
How do you know if a candle is a chemical change?
Can you reverse the change?
How do you know that baking bread is a chemical change and not a physical change?
Its a chemical change because its changing what it is (from dough to bread)
Is hydrofluoric acid attacking glass a physical or chemical change?
Does anyone know
When you burn magnesium in air what might show you a chemical reaction has taken place?
I don't know how you know afterwards but when you burn magnesium in air it burns this really bright white light.
Which change below is a chemical change?
dont know your out of luck
How do you know that a chemical change took place when sodium and clorine join to form table salt?
it is an ionic and exothermic reaction i.e. when it will take place heat will be liberated
