Answer:
As the sun's angle changes, (because of the rotation of the earth) the sun slowly begins to shine more or less sunshine slowly. When sunsets and sunrises occur, the color of the sky changes because the sunshine is starting to fade out or in.
I put it in my own words so you don't have to worry about plagiarism :)
It's most natural state has a charge of -2. So, a negative ion with two more electrons than is normal.
Answer:

Explanation:
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In this case, we can consider that the given heat of combustion is indeed the heat of reaction since it corresponds to the combustion of propane, which is computed by using the heat formation of all the involved species as shown below:

Thus, since the heat of formation of gaseous carbon dioxide is -393.5 kJ/mol, water -241.8 kJ/mol and oxygen 0 kJ/mol, the heat of formation of propane is:

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Transport of Na+ from a place of low concentration to a place of higher concentration. <u>This is the right answer.</u>
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The sodium-potassium pump is the most common and well-known example of active transport. At the cell membrane, the sodium-potassium pump moves 3 sodium ions out of the cell and two potassium ions into the cell per ATP. Examples of active transport include the uptake of glucose in the human intestine and the uptake of minerals and ions into the root hair cells of plants.
One of the greatest examples of active transport is the movement of calcium ions out of cardiomyocytes. Cells secrete proteins such as enzymes, antibodies, and various other peptide hormones. Amino acids are transported across the intestinal mucosa of the human intestine. The movement of ions or molecules across cell membranes to regions of a higher concentration is assisted by enzymes and requires energy.
Learn more about Active transport here:-brainly.com/question/25802833
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The magma from a volcano is cooled