RRB NTPC Exam 2016 will test you on Physical & Chemical Changes – the fundamental force that attracts objects together. Learn about Gravity and Take the Quiz that follows.
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RRB NTPC Exam 2016 #Daily Infographic on General Science (Chemistry)
They are usually easy to identify because they visibly alter matter. When ice melts, changing physical states, you can see water pooling in its place. When a crayon is used to draw, the crayon breaks into millions of tiny pieces and adheres to the paper. The color of the crayon, in your hand and on the drawing, is the same; only the size and shape of the matter has changed.
Here are some examples of physical changes.
- Bread crumples.
- Boiling water evaporates.
- The paper towels roll is built to undergo physical change–perforations make it easy to rip into smaller pieces.
- A sponge can expand when it soaks up water, or shrink as it dries.
They occur at the atomic level, which means we can’t actually see them happening. However, we can use all of our senses and other scientific meters to detect a chemical reaction as it occurs. There are three main signs to look out for when trying to identify a chemical change. They will not always signify the occurrence of a reaction, but they are often linked with chemical changes.
- the appearance of a new substance,
- irreversible change has occurred
- the absorption or release of energy.
Different types of chemical changes have names that describe the processes occurring. Here are some you might know.
- Oxidation (rusting)
TAKE THE QUIZ ON PHYSICAL & CHEMICAL CHANGES