Question

#1: Nitrogen (N) is made up of 99.632% 14N and 0.368% 15N. The atomic mass of 14N is 14.003 amu. The atomic mass of 15N is 15.000 amu. What is the average atomic mass of nitrogen?

A. 14.0 amu

B. 14.006 amu

C. 15.00 amu

D. 15.50 amu
**my answer: B.
but idk 100% :/

Answer 1

#2: Rhenium (Re) is made up of 37.4% 185Re and 62.6% 187Re. The atomic mass of 185Re is 184.953 amu. The atomic mass of 187Re is 186.956 amu. What is the average atomic mass of rhenium?

A. 187.00 amu

B. 186.397 amu

C. 186.207 amu

D. 186.00 amu
***My answer: C. 186.207 amu

Answer 2

#3: The mass number of an element is equal to which of the following?

A. number of electrons plus number of protons

B. number of protons plus number of neutrons

C. number of protons

D. number of isotopes
**My answer: B

Answer 3

#4: Silicon (atomic number 14) has three isotopes: 28Si, 29Si, and 30Si. What is the number of protons in an atom of silicon with the highest mass number?

A. 30

B. 29

C. 16

D. 14
***my answer: D. 14

not 100 % sure thooo :/

Answer 4

#5: What is atomic mass?

A. the average mass of all isotopes

B. the mass of the atom based on the mass of an atom of oxygen-16

C. the mass of the atom based on the mass of an atom of hydrogen-1

D. the mass of an atom based on the mass of an atom of carbon-12
***My answer: C

Answer 5

what do you think about those 5??

Answer 6

they're all right except #5 which is A

Answer 7

okay, so my answers are these?
1=B
2=C
3=B
4=D
5=A
??? ur 100% sure these are all correct like that?? :)

Answer 8

yes

Answer 9

great! thanks :)

Answer 10

great! thanks :)