Answer:
D. You can no longer tell if your original sample contained Na+ or K+.
Explanation:
Group reagents are the reagents which are used to separate a whole group of cations from the other groups of cations.
For example, for group 1 , the group reagent is HCl and for group 5, the group reagent is ammonium carbonate.
<u>When sodium chloride and potassium carbonate is used, it means we are contaminating our sample with foreign cations which may interfere in the process of detection. Also, we will not be able to decipher whether the sample has these ions in the initial or not as we have added them.</u>
A pure substance is a element made up of only one type of atom or molecule.
The scientists produced an adhesive that was made from carbon nano tubes. The adhesive has two different layers; the lower layer is composed of vertically aligned nano tubes while the upper layer is made up of curly nano tubes that are spaghetti - like in shape.
The adhesive device produced can hold a maximum force of 700 pounds while adhering to a smooth surface.<span />
Answer:

Explanation:
Given



Required
Determine the final mass
First we need to determine the total mass after the sample mass is added to an additional sample;



Next, divide the total mass by 3



The final mass is calculated as follows;



<em>Hence, the final mass is 17.560943085g</em>
Answer:
D: Increasing the amount of water.
Explanation:
Choice A: increasing the pressure can force the liquid to stay a liquid and affect the boiling point (decrease it).
Choice B and C: both involve colligative properties, adding a solute to water will increase the boiling point of water.
Choice D: just having more water does not change the boiling point of the water as this minimize the effect of any external factor.
<em>So, the right choice is: D: Increasing the amount of water.</em>