This question uses weighted averages.
Since the average mass of element A is 63.6 amu and the only two isotopes are 63 and 65,
63.6 = x% * 63 + (1-x%) * 65
If you don't want to calculate this (like me), you can look at the answer choices.
If it was 100% A-63, the weight would be 63. Cross off D.
If it was 50/50, the weight would be 64. Cross off C.
So since the weighted average is 63.6, you would expect there to be more A-63 than A-65, so B is the only answer that makes sense.
First convert the 2 temperatures to degrees K:
4 + 273 ---> 277 and 22---> 295
So using Charles' Law
V1 / T1 = V2 / T2
0.50 / 295 = V2 / 277
solving for V2 gives a volume of 0.469 L to nearest milliliter
The answer to this question is the "C3", it is the complement protein cascade which is in the same way of the classical pathway, alternate pathway and especially the lectin pathway after the point in the cascade where the activation of the C3 takes place. The C3 in chemistry refers to the convertase and an enzyme with propylene its basic raw materials in the industries.
The correct answer among the choices given is the last option A pH reading of 10 represents a basic solution. pH is a measure of the concentration of hydrogen ions of the substance. Solutions that have more OH– than H+ ions are bases. These are substances that are slippery to touch and has an astringent taste. It reacts with acids in a neutralization reaction forming salts.
