I need answer ASAP
Darla claims that the first periodic table developed by Mendeleev was not completely accurate, so it is not useful at all. Harmony argues that it helped establish the periodic table we use today, making it more credible. Who is correct and why?
Darla is correct, because a model that has any mistakes should be thrown out.
Darla is correct, because a good model would not need to change.
Harmony is correct, because Mendeleev’s model had all of the information correct in the first version.
Harmony is correct, because Mendeleev’s model made predictions that came true.

Another problem Mendeleev encountered was that sometimes the next heaviest element in his list did not fit the properties of the next available place on the table. He would skip places on the table, leaving holes, in order to put the element in a group with elements with similar properties.

Please mark me BRAINLIEST I HAVE ZER BRAINLIEST

Explanation:

see earlier

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.