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1. anonymous

2. anonymous

@Photon336

3. anonymous

i don't even have a clue. i never took chemistry so i don't know. my head hurts just looking at that question

5. anonymous

lololololol

7. anonymous

its okay bro thanks alot

no prob. good luck with your question

9. Photon336

@princestonA hey, for each isotope do the following. Step#1 write down the atomic mass for one of the isotopes. Step#2 convert the % abundance to decimal by putting the number over 100 Step#3 multiply the two numbers you'll get a number. just write this down and put a box over it to remember it. do this for each isotope and then add the numbers up to get the total average mass. Start with the first isotope they give you and tell me what you get. |dw:1444334821299:dw|

10. Photon336

This looks complicated but once you get it it's not that bad.

11. anonymous

Oh thanks alot is 28.09

12. anonymous

@Photon336 can you you do me one favor calculate the average atomic mass of rubidium. Rubidium has two isotopes, 85Rb and 87Rb. 85Rb has an atomic mass of 84.912 amu and occurs at an abundance of 72.17%. 87Rb has an atomic mass of 86.909 amu and occurs at an abundance of 27.83%. I wanna see the work so i know how to do it.

13. Photon336

Yeah sure

14. anonymous

huh?

15. Photon336

ok i'll try this in a sec

16. Photon336

$$\color{#0cbb34}{\text{Originally Posted by}}$$ @PrincestonA @Photon336 can you you do me one favor calculate the average atomic mass of rubidium. Rubidium has two isotopes, 85Rb and 87Rb. 85Rb has an atomic mass of 84.912 amu and occurs at an abundance of 72.17%. 87Rb has an atomic mass of 86.909 amu and occurs at an abundance of 27.83%. I wanna see the work so i know how to do it. $$\color{#0cbb34}{\text{End of Quote}}$$ |dw:1444335901174:dw| FOR 85 RB $84.912amu *\frac{ 72 }{ 100 } = 61.280 amu, 85RB$ For 87 RB $86.909amu*(\frac{ 27.83 }{ 100 }) = 24.186amu$ now we add them up $Rb^{87} + {Rb ^{85}}$ $(24.186+61.280)= 85.467 amu$ @PrincestonA you can check to see if this number is right by going to the periodic table. every element is the average atomic mass for isotopes. we check our value of 85.467 by looking at the periodic table and we see that these two values match so that's how we know our answer is correct. hope this helped.

17. Photon336

it's probably better that you see it done step by step,

18. anonymous

thank you sooooooo much pho Your the best dude

19. Photon336

yeah no problem, once you see how it's done the problem is not that bad