B, the opposing forces are the same, thus, the ball doesn't move back or forward.
The much of the sample that would remain unchanged after 140 seconds is 2.813 g
Explanation
Half life is time taken for the quantity to reduce to half its original value.
if the half life for Scandium is 35 sec, then the number of half life in 140 seconds
=140 sec/ 35 s = 4 half life
Therefore 45 g after first half life = 45 x1/2 =22.5 g
22.5 g after second half life = 22.5 x 1/2 =11.25 g
11.25 g after third half life = 11.25 x 1/2 = 5.625 g
5.625 after fourth half life = 5.625 x 1/2 = 2.813
therefore 2.813 g of Scandium 47 remains unchanged.
I think the answer would be dependent variable. An unknown or changeable quantity is called a dependent variable. It <span>is what you measure in the experiment and what is affected during the experiment. Hope this answers the question. Have a nice day.</span>
Answer:
It is either the third or fourth statement.
Explanation:
This is because exothermic reactions give off heat.
How do seed plants protect their embryos?
Reptilian embryos are protected from desiccation by a leathery shell. Similarly, sporophytes of both gymnosperms and angiosperms protect embryos within, and they also protect male gametophytes against desiccation using .....
