Answer: You know that monomers that are joined by condensation polymerization have two functional groups. You also know (from Part 6) that a carboxylic acid and an amine can form an amide linkage, jand a carboxylic acid and an alcohol can form an ester linkage.
Chemical indicators are the chemical reagents that show the change in reaction by changing color. Chemical indicators must be chosen with a narrow pH range.
<h3>What are indicators?</h3>
Indicators are the solutions or the substances used for the qualitative and the quantitative measurement by a change in color because of the absence or the presence of the sample concentration.
The chemical indicators cannot detect the exact pH and should be used with a narrow range of pH.
Therefore, option C. the narrow range of pH is the disadvantage of chemical indicators.
Learn more about chemical indicators here:
brainly.com/question/15114406
1. A - atoms
2. B - protons electrons and neutrons
Answer:
The element belongs to group 15 of the present periodic table
Explanation:
Isotopes have the same proton number, what differs is that they have different number of neutrons.
Now since the half-sum of their neutrons is 19, the total number of neutrons would be 19 * 2 = 38 neutrons.
Also, their masses add up to be 68, since the total mass equals sum of neutrons and sum of protons, this means that the total number of protons is 68-38 = 30
Since this is equal in both isotopes, this means that the proton number of the element is 30/2 = 15
The atomic number is the number of protons in the nucleus of an atom. Since the atomic number is 15, this element is phosphorus and it belongs to group 15 of the present periodic table
I believe it is element As, for arsenic.
