A chemical change is characterized of the formation of new substances or a chemical reaction. There are a number of observations that we can see if this type of change happens. One would be the formation of gas bubbles, this indicates that one of the products is a gas. Another observation would be a formation of a precipitate in the solution, it would indicate that the new solid formed is not soluble in the solution. A permanent color change in the solution would also indicate a chemical change because it may be that the new substance that is formed has its own distinct color when in solution.
When a substance is entering a phase change, the gain or loss of heat is a result of energy gained or lost in forming or breaking intermolecular interaction.
The constant temperatures occur when a substance is undergoing a phase transition. If heat is removed from a substance , such as in freezing and condensation , then the process is exothermic . In this instance , heat is decreasing the speed of the molecules causing then move slower.
Example : liquid to solid and gas to liquid .
These changes release heat to the surrounding.
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the value represented by 4.5x10-6 g is 0.0000045 g it is a representation in standard notation
To express enormous figures which are in standard notation like 1,300,000 or exceedingly minuscule quantities like 0.0000000000045, scientists use scientific notation. Scientific notation, also referred to as exponential form, is one of the earliest mathematical techniques. It is well regarded by practitioners. People use scientific notation to handle situations where numbers are too large or too small to be calculated easily. Scientists, engineers, and mathematicians all use this technique. where as standard notation is way writing numbers in normal decimal form. The scientific method id most convenient denoting numbers as the numbers will be either too big or too small.
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February or march probably
