Explanation:
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An elements is called a pure substance because it is composed of only one kina of atoms in a fix proportion.
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Answer : the box will move backwards with a force 10 N
Explanation :
F1 = 20 N
F2 = 30 N
F = F2 - F1 = 30 - 20 = 10 N
Double Displacement Reaction
An element from each of two compounds switch places.
Example: compound + compound ⇒ compound + compound
Chemical reactions are processes in which substances change into other substances. A chemical reaction takes place if one or more of these occur:
Color changes - Different combinations of molecules reflect light differently. A color change indicates a change in molecules.
Heat content changes- In all chemical reactions, the heat content of the reactants and the heat content of the products is never the same. Sometimes the difference is great and can be easily detected. At other times, the difference is slight and more difficult to detect.
Gas produced - Whenever a gaseous product forms in a liquid solution, bubbles can be seen. A colorless gas produced in a reaction of solids is much harder to detect.
Precipitate forms- Precipitates are insoluble products formed by a reaction taking place in a liquid solution. This insoluble product will eventually settle to the bottom, but might immediately appear by turning the clear solution cloudy.
Answer:
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Explanation:
The star with apparent magnitude 2 is more brighter than 7.
To find the answer, we have to know about apparent magnitude.
<h3>What is apparent magnitude?</h3>
- 100 times as luminous as a star with an apparent brightness of 7 is a star with a magnitude of 2.
- The apparent magnitude of bigger stars is always smaller.
- The brightest star in the night sky is Sirius.
- The brightness of a star or other celestial object perceived from Earth is measured in apparent magnitude (m).
- The apparent magnitude of an object is determined by its inherent luminosity, its distance from Earth, and any light extinction brought on by interstellar dust in the path of the observer's line of sight.
Thus, we can conclude that, the star with apparent magnitude 2 is more brighter than 7.
Learn more about the apparent magnitude here:
brainly.com/question/350008
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