Question

#1: The average atomic mass of hydrogen (H) is 1.008 amu. Hydrogen is made up of isotopes 1H, 2H, and 3H. What can you infer about the relative abundance of these isotopes?

A. 3H is most abundant.

B. 1H is most abundant.

C. All isotopes are equally abundant.

D. 2H is most abundant.
***Idk this one at all :(

Answer 1

since it's closer to 1, 1H is most abundant (b/c it's weighted right)

Answer 2

so #1 is B?? 1H??

Answer 3

#2: The most common isotope of chromium is 52Cr. How many protons does an atom of 52Cr have? Use the periodic table.

A. 28

B. 52

C. 80

D. 24
**My answer: B. 52

Answer 4

yep to both!

Answer 5

#3: Rhenium (Re) is made up of 37.4% 185Re and 62.6% 187Re. What is the number of protons in an atom of the least abundant isotope? Use the periodic table.

A. 75

B. 77

C. 100

D. 102
**idk :(

Answer 6

the number of protons NEVER changes within isotopes

Answer 7

#4: Hydrogen can exist with no neutrons, one neutron, or two neutrons. Which of the following is the symbol for an atom of hydrogen with the smallest mass number? Use the periodic table.

A. 1H

B. 2H

C. 3H

D. 0H
**My answer: D. 0H
but I'm not 100% sure :(

Answer 8

and what do u mean by that?? what's #3 then??

Answer 9

0H doesn't exist lol.,, it'd be 1H because one proton right?

Answer 10

oh so #4 is what??

Answer 11

#3 will be the amount of protons = atomic number of rhenium

Answer 12

#5: Oxygen has three isotopes: 16O, 17O, and 18O. In any given sample, 99.757% is 16O, 0.038% is 17O, and 0.205% is 18O. The atomic mass of each is as follows: 16O = 15.995 amu; 17O = 16.999 amu; 18O = 17.999 amu. What is the average atomic mass of oxygen?

A. 15.995 amu

B. 15.999 amu

C. 16.060 amu

D. 16.099 amu
***idk this one either :(

Answer 13

4 is A

Answer 14

so #3 is B. 77???

Answer 15

and okay, so 4 is A... what about 3 and 5? :)

Answer 16

#5 you have to calculate like you did with other ones
% x mass + % x mass +.... = atomic mass

Answer 17

#3 rhenium has atomic number what?

Answer 18

is this the answer to #5?

C. 16.060 amu

???

Answer 19

rh atomic numver is 45?

Answer 20

it's Re not Rh

Answer 21

#5 is A

Answer 22

ohhh then idk #3 :(

Answer 23

haha look at the periodic table!

Answer 24

6th period

Answer 25

kay i mixed up re with rh hahaa so it is 75.. so my answer to #3 is A. 75
???

Answer 26

YES :)

Answer 27

yayyy! so just making sure...
1=B
2=B
3=A
4=A
5=A
????

Answer 28

yes!

Answer 29

i have to go! byeee

Answer 30

aweomse! thanks :) byee thank you so much again!! :D