Explanation:
Using stratified random sampling, researchers must identify characteristics, divide the population into strata, and proportionally choose individuals for the representative sample. ... For example, individuals who are too busy to participate will be under-represented in the representative sample.
Answer:
<span>In ionic compounds, <u>Metals</u> lose their valence electrons to form positively charged Cations.
Explanation:
Metals have the ability to loose elctrons readily. For example metals of Group IA and Group IIA readily looses electrons in order to obtain Noble Gas Configuration. On the other hand Non-metals tends to gain electrons and acquire negative charge. While Ions are made when an an element gain or loose electrons. After loosing electrons element get positive charge which is called as Cation while on gaining electron it gets negative charge called as Anion.</span>
Answer:
Green
Explanation:
Positive: A strong green color in the flame indicates the presence of halogens (chloride, bromide, iodide but not fluoride).
Answer:
B. Household ammonia.
Explanation:
NH₃ is a base, so the solution always will be basic.
NH₃ takes the proton from the water. In conclusion we have free OH⁻ in medium, that's why the solution is basic.
NH₃ + H₂O → NH₄⁺ + OH⁻
- HCl + H₂O → H₃O⁺ + Cl⁻
This reaction makes an acid solution, cause the H₃O⁺
- Vinegar is a compound made of acetic acid.
CH₃COOH + H₂O ⇄ H₃O⁺ + CH₃COO⁻
This reaction also makes an acid solution, cause the H₃O⁺
- Pure water makes neutral solution. It is not acid, neither basic.
2H₂O ⇄ H₃O⁺ + OH⁻
<span>The choices are as follows:
h2o + 2o2 = h2o2
fe2o3 + 3h2 = 2fe + 3h2o
al + 3br2 = albr3
caco3 = </span><span>cao + co2
The correct answers would be the second and the last option. The equations that are correctly balanced are:
</span> fe2o3 + 3h2 = 2fe + 3h2o
caco3 = cao + co2
To balance, it should be that the number of atoms of each element in the reactant and the product side is equal.