An element is composed of a single type of cell. So we can expect only one kind of element. For example if it is a carbon element it will contain only carbon atoms.
We know that it is a certainty based on things such as the size, mass, brightness, etc. They can determine to within a relative level of accuracy the age. Of course they can be off by millions of years, but that’s pretty precise for a 10–20 billion year time period for the life of a star. BUT we absolutely cannot predict exactly when it will explode and we see supernovas in other galaxies, but the last one in the Milky Way that we observed was in the 1600s.
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When a solute in a solvent forms a solution, it is called dissolution. a solute is the primary substance that is dissolved in a liquid called the solvent. so what this means is that when something dissolves in something else. there are many factors that affect the rate at which a solute will dissolve.
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