Because its made of different materials so it could be strong
Answer:
The correct litmus test for an acid is:
blue litmus turns red
Explanation:
Litmus paper : It is a paper which contains 14 -15 dyes obtained from Lichens
It is also called <u>Acid-Base Indicator</u>
It is used to test whether the given solution is acidic or not.
If the solution is<u> acidic the litmus turns Red</u>
If the solution is<u> basic the litmus turns Blue</u>
<u>How to perform Litmus Test :</u>
Place the drop of given solution over the litmus paper.
If the Litmus paper is Blue initially and On adding a drop of given solution , it turn red then it indicate that the solution is acid with pH = 3 to 7
Red litmus paper does not change its color if the solution is acidic .
If the Litmus paper is Red initially and On adding a drop of given solution , it turn Blue then it indicate that the solution is alkaline . pH= 4 to 12
Blue litmus does not change its color in the presence of alkaline solution.
Based on the graph you can see that after introduction of the vaccine in 1960 there was a sharp decline in US measles cases. Then over the 1960s as immunization numbers increased the measles cases in the US once again sharply declined and except for the occasional breakout remained at 0 or near zero for decades.
The answer would be, D. because ive taken the test.