1. 
- The changing of liquid to a gas.
2. 
- The major source of pollution.
3. 
- Carbon dioxide and water vapor trapping heat given off by Earth.
4. 
- Layer absorbing ultraviolet rays.
5. 
- The changing of a gas to a liquid.
6. 
- Layer responsible for reflecting radio waves.
7. 
- The layer in which weather changes.
Event 1 is an example of a chemical reaction.
<u>Explanation:</u>
Whenever if two solutions are mixed, then if there is any color change, or evolution of any vapors, bubbles or gas formation or if there is any formation of a color or white precipitate confirms that the occurrence of a chemical reaction.
If nothing happens said above then it is said that there is no chemical reaction occurs.
Here in the event 1 a clear liquid in one beaker poured into clear liquid in beaker 2 then there is a formation of orange liquid, which means there is a formation of a new colored liquid confirms that the chemical reaction occurred.
Chlorine. Electronegativity rises as you go up and to the right on the periodic table.
2.258625 *10²³ oxygen atoms will be produced.
<h3><u>Explanation:</u></h3>
Decomposition reaction is defined as the type of reaction where one single reactant breaks to produce more than one product only by means of heat or other external factor.
Formula of magnesium oxide = MgO.
The molecular mass of magnesium oxide = 24 +16= 40.
So in 40 grams of magnesium oxide, number of molecules is 6.023 * 10²³.
So in 15 grams of magnesium oxide,, number of molecules is 6.023 *1023 * 15/40 = 2.258625 *10²³.
From one molecule of magnesium oxide, one oxide atom will be produced.
So number of oxide atoms with 100% yeild = 2.258625 *10²³
Carbonation isn’t a force that causes such
