Just so u know I do not know this for sure
carbon
potassium
phosphorus
plz tell if I'm right , if you know
Prions is the answer I took it
It will take 15 s to travel 6 cm
<h3>Further explanation</h3>
Given
distance versus time graph
Required
time travel
Solution
Caterpillar motion is a straight motion with a constant speed, so that the graph between distance and time forms a diagonal line
If we look at the graph, we can determine the time taken when the distance reaches 6 cm (y axis) by drawing a line to the diagonal line and cutting the x-axis as time, and we get 15 s
Or we can also use the formula for motion at constant speed:
d = v x t
With v at point 2,5 of 2/5 m / s, so the time taken:

It has 49 electrons as well. The amount of protons and electrons are equal.
Your answer is B and the element is Carbon
So what your looking for is matching isotopes. Isotopes are elements that are the same in amount of protons but different in mass meaning different number in neutrons. Because when you add the total protons and neutrons together you get your atomic mass. So this can be written as X=said element, top number above=different atomic mass, bottom number below=atomic number. Hope this help!!
Be careful because answer A has same masses but different atomic numbers so different atoms(elements)!!!