I believe that crude oil is derived from plants because it is made up of a liquid that is found beneath the earth surface so I guess you could go with plants it is not an animal or rock or salt so.. could be brainliest not 100% sure so if you are not sure go with your gut
Answer:
The differemt isotopes that differ in atomic mass
Explanation:
1A: The legs can be a adjusted, as well as the sand can be swapped out. It’s a very good design for running multiple tests.
1B: He could add books or something under the front or back legs in order to increase/decrease the incline, therefore imitating the hypothesis.
1C: He can change out the sand grains to finer ones, or coarser ones, and record his results of each test.
2: If he sets the model at a steep incline and tests it with coarse sand and fine sand, seeing which one makes a narrower, deeper hole.
Answer: 0.172 M
Explanation:
a) To calculate theconcentration of base, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

b) To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

The concentration of the phosphoric acid solution is 1.172 M