# Estimating for atomic number for an “unknown element” [duplicate]

A questions tells me there's this element with 3 isotopes (270.51 amu, 34.07% abundance; 271.23 amu, 55.12%; and 269.14 amu, 10.81%), and to solve for average atomic mass. I have done so and got 271 (270.758) for its atomic mass. Then it asks me to estimate its atomic number, and its location on the periodic table. How do I exactly "estimate"?

ps. I dont think this element actually exists...

## marked as duplicate by Tyberius, andselisk♦, Todd Minehardt, airhuff, JanNov 10 '17 at 11:04

• Note that, in general chemistry, the atomic mass unit (amu), which referred to the atomic mass of oxygen, is obsolete since 1961. – Loong Mar 24 '16 at 17:25
• You need at least four significant figures not 3 for the average atomic weight, but I'd give 5 in this case. // I know that there is some curve relating atomic number and atomic weight but I can't remember the name right now. // Peeking at the periodic table, Sg with atomic number 106 seems to fit. – MaxW Mar 24 '16 at 17:32
• See here: en.wikipedia.org/wiki/… the curve is shown here: en.wikipedia.org/wiki/… – MaxW Mar 24 '16 at 17:40
• @MaxW there is also a good atomic number vs. atomic weight answer here on chem.se: chemistry.stackexchange.com/questions/32158/… – pH13 - Yet another Philipp Mar 24 '16 at 17:50
• @ph13 - Thanks for the link! I upvoted Geoff's answer. I'm sure he wasn't the first to play with the equations, but he gave a really good answer. // It doesn't seem that the power law equation has a particular name which somewhat surprises me. – MaxW Mar 24 '16 at 19:37

• Welcome to Chemistry.SE! Take the tour to get familiar with this site. Mathematical expressions and equations can be formatted using $\LaTeX$ syntax. For more information in general have a look at the help center. At the moment this reads more like a comment than an actual answer - could you elaborate a little more, for example how you found it, because that is the actual question. With a bit more rep, you will be able to post comments on any question/answer. – Martin - マーチン Nov 9 '17 at 15:17