why is the atomic mass recorded in the periodic table as a decimal?

Answer 1

because that is the actual mass

the atomic "number" will be an even integer but the mass reflects the fact that there are different isotopes of the same element

for instance, carbon has a certain fraction of C-14 as well as the C-12

I'm believe it has other isotopes as well

the mass of any macro amount of carbon will be the result of the distribution of the isotopes

Answer 2

Well the atomic mass is as a decimal becuase the weight of protons and neutrons of a substance don't exactly equal to a whole number. Also you have 6.022 x 10^23 atoms of that substance in that atomic mass. But basicly its just that the protons and the neutrons which are mostly the mass of the atom since electrons are almost next to nothing don't equal to a whole number

Answer 3

It's not an actual mass of the Element-Isotope.It's an averaged out value. The decimal point is there to indicate a higher degree of precision and accuracy. If you weighed yourself on a scale that read;145 lbs. Then on another scale that read 145.362 lbs. Which is the more accurate or precise reading ?
If you wanted to know how many moles are in 1 metric ton of Lead. You need to know the atomic mass number.To know how many gams is equal to 1 mole of Lead(Pb).Which is equivalent to the Lead's atomic mass unit in grams. Dividing one metric ton 1 000kg by the amu of lead tells you how many moles of lead are in 1 metric ton of Lead. If the amu value for Lead is written to the hundreth decimal point degree of accuracy. You will get a more accurate answer. It makes all the difference on a larger scale. Like the decimal point on a % earnings in a savings or investment account in Banking. Would you deposit $100 000 into a bank that gives you 1.2% or 1.245 % monthly ?

Answer 4

The atomic mass is an average mass of all the isotopes of the element by percentage thus not a whole number.

Answer 5

Because it's the weighted average of the mass of all the isotopes of that element.

An isotope of an element has the same number of protons but differs in the number of neutrons.

For example, take carbon. Carbon has isotopes called carbon-12, carbon-13 and carbon-14. Carbon 12 has 6 protons and six neutrons, while carbon -13 and carbon-14 have six proton, and 7 nand 8 neutrons, respectively. The mass of carbon, 12.011, is thus the sums of the masses of carbon-12, carbon-13, and carbon-14, each multiplied by their per cent abundance divided by 100.

Answer 6

yes a weighted average of each isotope's mass times its abundance (%). So the actual weight is a whole number.

If an element had one isotope which was 100% and weighed 10, its mass would be 10. If it had two isotopes and each were 50%, with weights 10 and 11, the mass would be 10.5 and so on...

Answer 7

I was told that it was the average atomic weight of all that element's known isotopes.

Answer 8

It's a weighted average of all isotopes.