10 atoms. If there are 10 in the reactants you need the same number in the products
When a substance dissociates into OH- ions, they are classified as bases.
18. the blank should be "
"
19. the question seems to be answered.
20. 
Answer:
FORMULA: HCl PESO MOLECULAR: 36.46 g/mol COMPOSICION: Cl: 97.23 % y H: 2.76 %. GENERALIDADES: El ácido clorhídrico es una disolución acuosa de cloruro de hidrógeno.