Atomic Mass for Hydrogen

[Aaron Tang 2F]

What is the proper rounding for hydrogen? Would it be 1.01 amu or 1.008?

[Nova Akhavan 2F]

It depends on how many significant figures you would like to use. In my discussion today the TA used 1.0 amu for hydrogen. If the question does not provide you with a measurement to use, I would say use 3 - 4 significant figures to be safe.

[Kavya Anand 2B]

Honestly, it's up to you (since both values are considered acceptable), but personally, I'd use 1.008 amu because there's no harm in being more specific!

[Natalie Quilala 1I]

I believe that either 1.01 amu or 1.008 amu would work as the atomic mass of hydrogen. That being said, specificity is an important factor in attaining the most accurate answer. For that reason, I would choose to use 1.008 amu for the atomic mass of hydrogen.

[loganchun]

Hi, I would use 1.008 for the atomic mass of hydrogen to be safe because it is more accurate. Usually on a problem, you don't want to round until you have your final answer to be the most exact. Also, the periodic table on Professor Lavelle's website has the atomic mass of hydrogen as 1.00794. Hope this helps!

[tim_villasenor 1k]

Going off of Natalie. It is better to be safe and just go with the most accurate atomic mass possible. Even though there is not a huge difference in this case, if you were to round very slightly in the early parts of a calculation, this could compound and lead to bigger effects later on.

[Mia Hansen 2I]

Yes, I agree with the above. Plus, it's probably a good idea to have enough sig figs so that molar mass conversions are not your limiting/ lowest number of sig figs used for sig fig rounding purposes at the end of a problem.

[Emily Ngo 1E]

Hi Aaron,
Although either is fine, I think it just depends on what periodic table you are looking at. Also, if a problem gives you the atomic mass of Hydrogen, then you should definitely use the mass that was given. However, the difference is so small I don't think it actually matters in the big picture.

[Janys Li - 1L]

Hi!

For most cases, like in exams, I think going to 2 decimal places is fine. However, for some really accurate calculations, if you don't get a desired answer (like when calculating the empirical formula), try going to more degrees of accuracy and see if that gives you a better answer.

[Harsimer Bal 3K]

Hi! If you are completing a multi-step problem, I would avoid rounding the atomic mass of hydrogen to a smaller amount of sig figs unless it is your final answer as rounding can change your final answer. Another idea would be to look at the number with the least amount of sig figs in a given question and base your rounding for hydrogen's atomic mass off of that.

[Caitlyn Lo 2F]

Hi!

I agree with what everyone is saying in that you should probably use 1.008 for the atomic mass of hydrogen so that your calculations are more exact.

[emily3L]

I would use 1.008 to be as precise as possible, unless the problem gives 1.01.

[KatieWu 1E]

I always use 1.01 for the mass of H and the answers haven't been off, but if you want to be extra safe I think you should use 1.008 to be extra precise.

[masontsang]

Hi! I would use 1.008 g/mol as Hydrogen's atomic mass and then express your answer in the proper number of sig figs at the end. This would help make your answer as precise as possible! I hope this helps!

[HaleyC 2F]

Hey, as everyone said 1.008 is the safest to use. Sometimes I do use 1.01 when there is rounding involved, but its easier to just use 1.008

[Charlie Gravereaux]

In my experience, I've always used 1.01 as the atomic mass for hydrogen, and I've never had an issue with sig figs or getting the correct answer. However, I also believe it depends on the situation, if you are already given atomic masses in the problem and they have 4 sig figs or more, then maybe use 1.008.

[erud]

It depends on the number of sig figs in the problem, but I tend to go with 1.008 amu just to be more accurate.

[SerenaSabedra]

I prefer to use the most specific numbers possible until the end when I round, but I think that 1.01 is still accurate enough that it could go either way. :)

[AJackman]

I find it useful to use the most specific number available to you while in the midst of calculations, and then reducing the sig figs to those of the least significant one for your answer. So I would use 1.008 and then round at the end.

[205705413]

Personally, I prefer using 1.008 amu because it is more accurate. However 1.01 amu is also good. It shouldn't influence the accuracy of your answer too much in the end.

[Kaitlyn_Urquilla_1I]

I always start off using 1.008 just to be safe and then round using the appropriate number of sig figs once I have finished all of my calculations. I do this to ensure that I get the most accurate answer that I can and just in case we do need 3 or 4 sig figs anyways.

[Jessica Arcos 2H]

I like to use 1.008 because it will get me a more accurate answer but I think it just depends on what you prefer and the number of sig figs its asking but other than that there shouldn't be a really big difference in your final answer.

[Daniela G 2C]

You can use whichever one you prefer, I personally use 1.008. If you use one over the other, there isn't much of a difference. Both lead you to your final answer.

[Meia Schram 1J]

I think using 1.008 is the safer option since that is what is listed as the mass on the periodic table he provides but if a problem has less sig figs then it could be reasonable to use 1.01.

Hope this helps!

[Carmen Kim 3I]

I believe both values, 1.01 and 1.008, work. However, to be more accurate, I would use 1.008 rather than 1.01 because rounding up early would definitely make a huge difference later in approaching the final answer part.

[Peter Fernandez 2K]

I personally prefer using 1.01 when significant digits aren't specified!

[Joshua Lance Yumul 1F]

I agree with everyone who replied above. I prefer 1.008 since this number would give the most accurate number while computing.

[Hannah Choi 1K]

1.0, 1.01, 1.008, 1.0079, ...
Like what everyone else said, it really just depends on the situation. Of course, the more sig figs you use, the more accurate your result will be, but all in all, just use whatever it is you are most comfortable with.

[Megan Cai 1H]

You should round according to your significant figures. But, it might be better to use 1.008 because it is more accurate and then round for sig figs at the end when you reach your final answer.

[madelyn kelly 1I]

I personally would use 1.008 or 1.0078 because it is more exact than using 1.01 and Dr Lavelle's periodic tabic table uses 1.0078. When doing precise calculations, the rounding could cause your answers to be off, and if there were ever a multiple choice situation, rounding incorrectly could result in getting a value that isn't an answer choice.

[Joseph Liao 3C]

In most of the periodic tables I have come across, hydrogen has an atomic mass of 1.008 amu, so I think this is generally as specific as we will need to be within this class. I personally wouldn't use anything rounded, as the rounding error could add up during the course of a problem, so I would just stick with 1.008!

[Arad_Badiee_2B]

I would use 1.008 since is closer to the actual value for the amu of hydrogen.

[Madelyn_Rios_2c]

If the measurement wasn't provided, use 1.008 for the atomic mass since it would be more accurate. You want to wait to round at the very end to get the most accurate answer.

[Neha Jonnalagadda 2D]

I would use 1.008 just because its better to be more specific, but at the end of the day it shouldn't affect your final answer too much if you use either. 3-5 significant figures is usually a good zone to be in for a final answer as well.

[205793570]

Hi!, it depends on how many significant figures you would like to use. I personally would use 1.0 amu for hydrogen. If the question does not provide you with a measurement to use, I would say use 3 - 4 significant figures should be fine.

[madeleinewright]

I would generally use 1.008 amu for the atomic mass of hydrogen because it is better to be more specific and accurate, but either one should work.

[Kaitlyn_Urquilla_1I]

Hi! You can use either but it really depends on how many sig figs you need your answer to be. If you need 4 sig figs, I would recommend not rounding until the very end and using 1.008 to avoid a less specific answer.

[Arad_Badiee_2B]

Hi! I would use 1.008 amu as I don't see how being more specific can hurt mort of the time. Hope this helps!

[Jieun 2C]

I think both would work but I would use 1.008 to be more accurate as it is closer to the atomic mass of hydrogen.

[Mia Orr 3B]

1.008 would be the more accurate value to use for the atomic mass for hydrogen, which will lead to a more accurate answer in the end!

[Amaris Cagungun 1F]

I use 1.008 to be as accurate as possible.

[Nathalia Garibay 1D]

Does anyone know if there are any instances in which we have to use 2.00 g/mol and not 1.00 g/mol as the mass for hydrogen because hydrogen is a diatomic?

[205819952]

I would use 1.008 for the atomic mass of hydrogen because it is more accurate.

[Maia Holmes Kueny 1C]

I use 1.01.

[AndreyCastellanos 3H]

use 1.008 g/mol as Hydrogen's atomic mass and then express your answer in the proper number of sig figs at the end