Explanation:
number of particles or atom = number of moles × Avogadro's number
number of atoms = 12.34 × 6.02 × 10^23
= 7.43 × 10^24 atoms
Answer:
Both oil and gasoline molecules are nonpolar, while water is polar. Nonpolar solvents have a tendency to dissolve other nonpolar molecules.
Explanation:
Molecules may be categorized as "polar" or "nonpolar" according to <em>difference in the atom's electronegativity.</em>
<u>Water is polar</u> because it consists of two types of atoms that<em> do not cancel out each other.</em> It is made of two atoms of Hydrogen and only one atom of Oxygen. This makes the Oxygen<u> partially negative</u> and the Hydrogen <u>partially positive.</u> This allows them to readily bond with other polar molecules like sugar. However, it cannot mix freely with oil and gasoline because<em> both of these are nonpolar. </em>Nonpolar molecules do not have much difference when it comes to their atoms' electronegativity. <em>Therefore, they have the tendency to dissolve molecules which are nonpolar as well. </em>This explains why oil molecules can mix freely with gasoline.
Answer: A. The extra electrons start to fill higher sublevels in the energy level.
Explanation:
Answer:
C. Trp D. Phe E. Tyr
Explanation:
The concentration of a protein has a direct relation with absorbance of the protein in a UV spectrophotometer. The formula which relates concentration with absorbance is described as under:
A = ∈ x c x l
where, A = Absorbance
∈ = Molar extinction co-efficient
c = Concentration of absorbing species i.e. protein
l = Path length of light
Tryptophan (Trp), phenylalanine (Phe ) and tyrosine (Tyr) are three aromatic amino acids which are used to measure protein concentration by UV. It is mainly because of tryptophan (Trp), protein absorbs at 280 nm which gives us an idea of protein concentration during UV spectroscopy.
The table depicting the wavelength at which these amino acids absorb and their respective molar extinction coefficient is as under:
Amino acid Wavelength Molar extinction co-efficient (∈)
Tryptophan 282 nm 5690
Tyrosine 274 nm 1280
Phenylalanine 257 nm 570
In view of table above, we can easily see that Molar extinction co-efficient (∈) of Tryptophan is highest amongst all these 3 amino acids that is why it dominates while measuring concentration.
I think the correct answer from the choices listed above is the first option. The Greeks were the first to use the term atom. In 450 BCE, Democritus coined the term átomos which means "uncuttable" or "the smallest indivisible particle of matter".
