No need to add. Use the elemnts mass number, which is the number of protons plus the number of neutrons
The number of protons added to the number of neutrons in a nucleus give that isotope's atomic weight.
The sum of the oxidation numbers in the phosphate ion (PO4^3-) is -3. Each oxygen atom has an oxidation number of -2, totaling -8. The oxidation number for phosphorus is +5 to offset the oxygen atoms and give a total charge of -3 for the ion.
With element X having oxidation numbers +3 and +5, compounds can form with element Z having oxidation numbers -2 and -3. Some possible compounds could be XZ2 (oxidation numbers cancel out) and XZ3 (oxidation numbers cancel out).
A chemical compound called ethyl mercaptan is added to LPG to give it a distinct smell, also known as odorant. This odorant is added as a safety measure so that leaks can be easily detected by people through the characteristic smell.
The oxidation number of Cr in K2Cr2O7 is +6. This can be determined by assigning the oxidation number of +1 to each K atom, the oxidation number of -2 to each O atom, and applying the rule that the sum of oxidation numbers in a neutral compound is zero.
-78
No. Two odd numbers added together always give an even number. Two even numbers added together always give an even number. An odd and an even number added together always give an odd number. So, if we have 5 odd numbers - a, b, c, d and e a + b will be even c + d will be even So if (a + b) + (c + d) is even, adding e to that will have to be an odd number - but 50 is even, so it cannot be done.
The middle number for 150 and 280 is 215. Here's how you work it out: Add the two numbers together which makes a total of 430. Then you divide the number by the number of numbers you added together to give you your answer.
Because 2 is a prime number and 2 added to any other prime number will give an odd result.
28
59
20,21
-3
-4 and -4
8 & 16
8 and 9
The midpoint of a line segment would be to add up all of the numbers in the segment. Then divide by the number of numbers that were added. For example if a 1, 3, and 8 were added, divide by 3. This will give the midpoint of the line segment.