Answer:
See below.
Step-by-step explanation:
Formula:

First term: n = 1

Second term: n = 2

Third term: n = 3

Fourth term: n = 4

Tenth term: n = 10

You would use the formula for the specific term you wish to find;
The formula is:

a = starting value of the sequence
d = the common difference (i.e. the difference between any two consecutive terms of the sequence)
n = the value corresponding to the position of the desired term in the sequence (i.e. 1 is the first term, 2 is the second, etc.)
Un = the actual vaue of the the term
For example, if we have the arithmetic sequence:
2, 6, 10, 14, ...
And let's say we want to find the 62nd term;
Then:
a = 2
d = 4
(i.e. 6 - 2 = 4, 10 - 6 = 4, 14 - 10 = 4;
You should always get the same number no matter which two terms you find the difference between so long as they are both
consecutive [next to each other], otherwise you are not dealing with an arithmetic sequence)
n = 62
And so:
-4d + 2(3+d)= -14
distribute the 2(3+d)
-4d + 6+ 2d= -14
Combine the like terms
-4d + 2d + 6= -14
-2d + 6 = -14
subtract 6 to -14
-2d = -20
divide by -2
d= -20/-2
d= 10
Check your answer
-4(10) + 2(3+ 10) = -14
-40 + 6 + 20
-40 + 26= -14
Answer:
9.03x10^16---------1.5x10^-7 helium
2.709x10^24-------4.5 nitrogen
1.9264x10^28-------3.2x10^4 hydrogen
4.8782x10^14--------8.1x10^-10 xenon
Step-by-step explanation: i got it right PERIOD PURRRRR