Answer:
each group of the periodic table.
example group 7 - fluorine, chlorine, bromine, iodine, astatine, tennessine
Answer:

Explanation:
When adding or subtracting values, you must round your answer to the same "place" as the measurement with its last significant figure furthest to the left.
That is, you round off to the same number of decimal places as the measurement with the fewest decimal places.

The measurement of 28.1 cm has one digit after the decimal point, so you round the sum to have only one digit to the right of the decimal.
However, the number to be dropped (51) is greater than 5 with only zeros or nothing following the 5.
You must round up the answer. You increase the last significant digit by one.

[H+][OH-]=10-¹⁴
We are using this formula because we need to find the H+
substitute the value given for hydronium ion for OH-
[H+][4.19×10⁵]=10-¹⁴
[H+]=10-¹⁴÷4.19×10⁵
[H+]=2.387×10-¹⁹
Then the pH of the solution will be
pH= –log¹⁰ [H+]
pH = –log¹⁰ [2.387×10-¹⁹]
pH= –log¹⁰2.387+19log¹⁰
= –0.378+19
pH =18.622
The answer is 4.3.... that acid rain can range from 3-4 on a pH scale