The purpose of using distilled water in the cuvette of the spectrophotometer is to calibrate the instrument. It is generally considered that distilled water shows zero absorbance and 100 % transmittance. So, to zero out the absorbance of compounds other than the analyte being determined, distilled water is used as a blank.
If the unknown being determined is prepared using ethanol as the base solution, the blank used must be ethanol. This is because absorbance if any from the solvent, ethanol must be zeroed out as when the measurement of the actual unknown is being made, the absorbance of the solvent does not interfere.
Answer:
Kapilari lebih kecil dan paling banyak saluran darah, mereka membentuk sambungan antara vesel yang membawa darah dari pendengaran (arteri) dan vesel yang mengembalikan darah ke jantung (urat)
Fungsi utama kapilari ialah pertukaran bahan antara sel darah dan tisu.
Veins membawa darah ke arah jantung; selepas ia melewati kapilari dan masuk melalui urat terkecil (venules).
Arteri membawa darah dari jantung; arteri sistemik mengangkut darah oksigen dari ventrikel kiri ke tisu badan.
Explanation:
(translated version)
Why blood capillary walls differ from veins and arteries
Capillaries are smaller and the most numerous of the blood vessels, they form the connection between the vessels that carry blood away from the hear (arteries) and the vessels that return the blood to the heart (veins)
The primary function of the capillaries is the exchange of materials between the blood and tissue cells.
Veins carries the blood towards the heart; after it passes through the capillaries and enters through the smallest veins (venules).
Arteries carries blood away from the heart; systemic arteries transport oxygenated blood from the left ventricle to the body tissues.
he arsenic acid or arsenate hydrogen as it is also known to this compound (H 3 AsO 4 ) is the acid form of <span>ion </span>arsenate , AsO<span>4 </span>3- , one anion trivalent in which arsenic has an oxidation state of + 5. Chemically, arsenates behave in a similar way tophosphates .
There is another compound derived from this one that is the arsenious acid or arsenite of hydrogen
<span>NaCl is poster-compound for ionic bonding. The bonds in NaCl have about 70% ionic character, making the bond highly polar. its overstatement to state that there is actual ion in NaCl with +1 and -1 charge but actual charge of Na and Cl is +1 and -1 ion, since Nacl exist as a network of highly charged particle and not discrete molecule, NaCl particle does not exhibit intermolecular forces.
Water molecule on other hand exhibit London dispersion force, keesom force, and hydrogen bonding.
The polar water molecule are attracted to the polarized Na and Cl atoms. This is what allow NaCl(s) to dissolve and ionize in water. Therefore type of attraction in NaCl is ion-dipole attraction.</span>
Answer:
when they have eight valence electrons.
Explanation:
When atoms do not have a full valence shell, the atoms are more likely to react with other and vice versa.
