Answer:
The correct answer is:
<em>(1) It is important that the sample is dissolved in just enough hot solvent. </em>
Explanation:
The process of recrystallization is important to eliminate the impurities and to obtain better crystals of the solid. The solvent used to perform the recrystallization must have a high dissolution power of the substance to be recrystallized and a low dissolution power of the impurities. This is in order to eliminate most impurities. Furthermore, <em>It is important that the sample is dissolved in just enough hot solvent </em>because this should be easy to remove after the recrystallization and the crystal should form easily when the solution cools. Also, it is better to add the hot solvent to solubilize the crystals and keep the impurities insoluble, instead of adding the cold solvent and heating the solution. Additionally, the process of cooling the solution must be done slowly to obtain large and fewer crystals. A fast ice-cooling will form smaller crystals.
Answer:
I would say that it is the bond called complementary hydrogen bonds
Explanation:
The nucleotides in a base pair are complementary which means their shape allows them to bond together with hydrogen bonds. The A-T pair forms two hydrogen bonds. The C-G pair forms three. The hydrogen bonding between complementary bases holds the two strands of DNA together.
Answer:
There is NO cure for Down Syndrome
Explanation:
Down syndrome cannot be cured. Early treatment programs can help improve skills. They may include speech, physical, occupational, and/or educational therapy. With support and treatment, many people with Down syndrome live happy, productive lives
Nit<u>ITE</u><u /> is NO<u>2</u><u />
nitr<u>ATE</u><u /> is NO<u>3</u><u />
