Question

Gallium has a weighted average atomic mass of 69.7 and two naturally occurring isotopes: gallium-69 and gallium-71. Gallium-69 has a relative abundance of 60.1% and a mass of 68.9. The relative abundance of gallium-71 is 39.9%. Based on this information, what is the mass of gallium-71?
71.1 g/mol
71.1 g/mol
70.9 g/mol
70.9 g/mol

Answer 1

what have u done so far?

Answer 2

i was hoping you could help me start

Answer 3

This is a pretest so idk too much of this stuff

Answer 4

sorry its lagging so bad

Answer 5

No worries

Answer 6

okay
Gallium has a weighted average atomic mass of 69.7

isotopes:
Gallium-69 has a relative abundance of 60.1% and a mass of 68.9.

The relative abundance of gallium-71 is 39.9%.

Based on this information, what is the mass of gallium-71?

so the formula is like this
\[\frac{ \sf (PAOI_1 \times mass~of~isotope_1) \times (PAOI_2 \times mass~of~isotope_2) }{ 100}\sf =average~ atomic~ mass\]
PAOI = percentage abundance of isotope

Answer 7

you have isotope 2 isotopes so i made the formula according to it

so u have isotope number 1(Gallium-69) and isotope number 2 (gallium-71)
isotope number 1 has percentage abundance and mass
isotope number 2 has percentage abundance given but MASS is missing so is unknown X
and you are given average atomic mass which is 69.7

Answer 8

use the formula and find unknown X mass of gallium-71

Answer 9

oh wait sorry my mistake there!

Answer 10

\(\sf \frac{(PAOI_1 \times mass~of~isotope_1) + (PAOI_2 \times mass~of~isotope_2)}{100}= average~ atomic~ mass\)

Answer 11

corrected

Answer 12

its 70.9

Answer 13

right?

Answer 14

sec let me calculate lol

Answer 15

And when you're done can yu help me with one more please?

Answer 16

yep u r correct :3

Answer 17

yep sure as long as i can i will help

Answer 18

The elements located in the first column, or group, in the periodic table all share a similar electron configuration. If the atom is neutral, how many electrons are found in the outermost shell of each of these elements?

Answer 19

1
2
3
4

Answer 20

neutral means 0 charge
what do u think?

Answer 21

is it 1?

Answer 22

how many electrons do group 1 elements have in their outermost shell?
that is when the atom is in neutral state
when atom loses or gains electrons -in other words its electron number on outermost shell increases or decreases from its original number of electrons - is when the atom becomes charged

Answer 23

so yeah
bingo!

Answer 24

You're the best, thanks ! (:

Answer 25

no problem :))