Hello @sheglow. You did a good job explaining why bleach and ammonia should not be mixed. However, there are two things that I would suggest you do for your future article to enhance readability:

• Use bullet point or any numbering system

The following chemicals are produced when ammonia is mixed with bleach;
Hydrochloric acid (HCl), chlorine (Cl), chlorine gas (Cl2), chloramine (NH2Cl), hydrazine (N2H4), sodium chloride (NaCl), water (H2O).
Note: except water and salt, all other chemicals are toxic

This sentences can be made into point form so that it would appear neat.

• Give some line to an equation

In order to understand what bleach is, we have to know more about chlorine gas because it is the basis of bleach. The sodium hypochlorite has a chemical formula NaOCl. Combination of this sodium hypochlorite and ammonia results into a reaction below NaOCl + 2NH3 --> 2NaONH3 + Cl2.
From the reaction above, chlorine gas is released from the sodium hypochlorite. The gas released if inhaled is very harmful and can deteriorate one’s health. Chemical properties of chlorine, number of chemical bond chlorine can form and valence of chlorine has to be understood in other to understand chlorine gas effects on the body. Chlorine belongs to group seven on the periodic table so; they are almost unreactive because the electrons on its outer shell remain one to form an octet.

It would be better if you write it like this:

In order to understand what bleach is, we have to know more about chlorine gas because it is the basis of bleach. The sodium hypochlorite has a chemical formula NaOCl. Combination of this sodium hypochlorite and ammonia results into a reaction below:

NaOCl + 2NH3 --> 2NaONH3 + Cl2.

From the reaction above, chlorine gas is released from the sodium hypochlorite. The gas released if inhaled is very harmful and can deteriorate one’s health. Chemical properties of chlorine, number of chemical bond chlorine can form and valence of chlorine has to be understood in other to understand chlorine gas effects on the body. Chlorine belongs to group seven on the periodic table so; they are almost unreactive because the electrons on its outer shell remain one to form an octet.

That would be nice to read don't you think? This is only my opinion. Good luck and keep on STEM-ing.