Answer:
2. All the naturally occurring isotopes of Mg.
Explanation:
You want to know the atomic mass of the magnesium you use in the lab. That’s “natural” magnesium. So, you must use the weighted average of all the naturally occurring isotopes in natural Mg.
1. and 3. are <em>wrong</em>. You won’t get the correct mass for natural Mg if you use only the artificial isotopes for your calculation.
4. is <em>wrong</em>. You must use all the naturally occurring isotopes. The two most abundant isotopes of Mg account for only 90 % of the atoms. If you ignore the other 10 %, your calculation will be wrong.
Answer:
A desinfecção
Explanation:
A desinfecção é o processo no qual o cloro é adicionado para matar microorganismos patogênicos prejudiciais, como bactérias, vírus, etc. Este é um processo químico e biológico. alguns desinfetantes comuns são cloro, dióxido de cloro e ozônio.
Answer:D. Compound.
Explanation:
A compound is defined as a pure substance: formed when two or more elements chemically combine to form bonds between their atoms.
Answer:
Active transport
Explanation:
Active transport is defined as the movement of ions or molecules from a region of lower concentration into a region of higher concentration by the use of energy. Two examples of active transport include the uptake of glucose in human intestine and the absorption of mineral ions into plant roots.
Active transport requires energy because it involves the movement of molecules against an existing concentration gradient.
