Answer:
magnesium= +2
aluminum= +3
phosphorous= -3
lithium= +1
fluorine= -1
Explanation:
As fluorine having seven valance electrons in its outer most shell with atomic number nine. And for completing its outer most shell it needs one more electron that is why it form ion of -1 value.
Now Aluminum has three electrons in its outer most shell with atomic number 13. So it need to lose these three electrons in order to be in stable state that is why it have ion in +3 state.
Same rule apply for other elements too.
Answer:
Er-144 -------> Dy-140 + He-4
Explanation:
Alpha decay is the release of a hydrogen nucleus. So the original atom will decrease the mass by 4 and the atomic number by 2.
Answer:
Density of concentrated H2SO4 = 1.99g/cm^3 = 1991.79Kg/m^3
Explanation:
mass of empty flask = 78.23g mass of flask filled when with water = 593.63g.
mass of flask filled when with concentrateds sulfuric acid, H2SO4 = 1026.57g
Mass of water = (mass of flask filled when with water) -
(mass of empty flask) = 593.63g - 78.23g = 515.4g
Volume of flask = volume of water = volume of concentrateds sulfuric acid, H2SO4 =
(mass of water)/ density of water) = 515.4g/1.00g/cm^3 = 515.4cm^3
The density of concentrated sulfuric acid is given by
Density of concentrated H2SO4 = (mass of H2SO4) ÷ (volume of H2SO4) = 1026.57g/515.4cm^3 = 1.99g/cm^3 = 1991.79Kg/m^3
hey there!:
A) Knowing theatre the protease is showing the highest activity at pH 4-6, implies that the amino acid that amino acid that it is acting in is an amino acid with a basic side chain. Therefore, the residues can be any one of the three basic amino acids being histidine, arginine or lysine , having basic side chains at neutral pH.
b) The mechanism of reaction of cysteine proteases is as follows:
First step in the reaction is the deprotonation of a thiol in the cysteine proteases's active site by an adjacent amino acid with a basic side chain, which might be a histidine residue. This is followed by a nucleophilic attack by the anionic sulfur of the deprotonated cysteine on the substrate carbonyl carbon.
Here, a part of the substrate is released with an amine terminus, restoring the His into a deprotonated form, thus forming a thioester intermediate, forming a link between the carboxy-terminal of the substrate and cysteine, resulting in thiol formation. Thus the name thiol proteases. The thioester bond is then hydrolyzed into a carboxylic acid moiety while again forming the free enzyme.
C) cysteine proteases have a pka of 8-9 but when they are deprotonated by a His residue, their pka would come down to 6-8, which would be their optimal pH for functioning. This is because there is a deprotonation of the thiol group , later restoring the HIS deprotonated form and then formation of a thioester bond. This thioester bond when hydrolysed will a carboxylate moeity , which is responsible for bringing the pH down towards a more acidic side.
d) at the optimal pH , the fraction of deprotonated cysteine and protonated B will be equal which will change with the change in pH.
Hope this helps!