D. <span>carbon and hydrogen</span>
⁴⁰Ar
N(e)=18
N(p)=18
N(n)=40-18=22
⁴⁰K
N(e)=19
N(p)=19
N9n)=40-19=21
⁴⁰Ca
N(e)=20
N(p)=20
N(n)=40-20=20
The question that will best help the student to classify the material is; "is the material malleable or ductile?"
Generally, materials can be classified as metals or non metals. There are properties that are particular to metals and there are properties that are particular to nonmetals and these properties can be used to identify each one of the materials.
The question that will best help the student to classify the material is; "is the material malleable or ductile?" These metallic properties.
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Missing parts;
A student is trying to classify an unidentified, solid gray material as a metal or a nonmetal. Which question will best help the student classify the material? A. Is the material malleable or ductile? B. Does the material feel hard to the touch? C. Will the material float in water? D. Does the material feel rough or smooth?
Answer:
12.5 µg
Explanation:
We are given the absorbance from the calibration curve:
A = 0.0182 x + 0.007
A = 0.234 ( It is already corrected, do not need the blank value )
so we can solve for x, the quantity of protein
x = ( 0.234 -0.007 )µg / 0.0182 = 12.5 µg
Note we are given the value for a blank solution but we do not need it for the absorbance of our sample since it is already corrected as stated in the question. If it were not a corrected absorbance ,we will need to correct the absorbance value. The absorbance of the blank is caused by some absorption from the solvent, cuvette, internal reflection, etc.
The cell must go through mitosis and chromosomes in the nucleus must double
