The ozone layer of the Earth's atmosphere is what protects living things from too much ultraviolet radiation, if that's what you're asking about.
By being an alternative route to the reaction with a lower activation energy.
Answer:
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed.
To find the ratio of the the combination for the ion, write the charge of the cation as the subscript for the anion, and the charge of the anion as the subscript of the cation. This will make the charges effectively cancel and you will be left with a neutral ionic compound. Remember, that an ionic compound is made up of a metal and a nonmetal.
For Ca2+ and Cl-, you will get the neutral compound to be CaCl₂.
Hey there!
The equivalence is point in a titration is the point at which you have neutralized all of your base/acid with your titrant acid/base from a buret. This can be seen with indicators which change color at the equivalence point in a titration to signal to you that all of your base/acid has been reacted with. For example, all your molecules of OH⁻ from a NaOH base in a beaker have been neutralized by H⁺of HCl acid from your titrant in a buret leaving only Na⁺ ions and Cl⁻ ions and neutral H₂O molecules.
