13. D
14. A
15. C
16. B
17. F
18. E
Answer: An atom can join with other kinds of atoms.
PLEASE GIVW ME BEAINLY LOLLL
Answer : The percentage reduction in intensity is 79.80 %
Explanation :
Using Beer-Lambert's law :
where,
A = absorbance of solution
C = concentration of solution = 
l = path length = 2.5 mm = 0.25 cm
= incident light
= transmitted light
= molar absorptivity coefficient = 
Now put all the given values in the above formula, we get:
If we consider = 100
then, 
Here 'I' intensity of transmitted light = 20.198
Thus, the intensity of absorbed light 
= 100 - 20.198 = 79.80
Now we have to calculate the percentage reduction in intensity.
Therefore, the percentage reduction in intensity is 79.80 %
I think the answer is number D…. I think
<h3><u>Answer;</u></h3>
The statements that are True are;
- Upon binding a molecule of oxygen, Hb undergoes a conformational change that makes the binding of subsequent O2 molecules easier.
- The conformational change induced in Hb upon binding oxygen is the result of a small movement (0.2 Å) of the iron cation in the center of heme.
- Site-directed mutagenesis studies have indicated that the cooperativity of O2 binding in Hb is attributable to the movement of the F helix in Hb.
<h3><u>Explanation</u>;</h3>
- Hemoglobin is a key pigment in the blood that transports oxygen gas to all the tissues in the body. It is made up of two types of chains; that is two alpha chains and two beta chains.
- in its deoxygenated state hemoglobin has a low affinity for oxygen compared to myoglobin. When oxygen is bound to the first subunit of hemoglobin it leads to subtle changes to the quaternary structure of the protein. This in turn makes it easier for a subsequent molecule of oxygen to bind to the next subunit.
