WorksheetsAverage Atomic Mass
Total questions: 25
Worksheet time: 25mins
4.35% of all X atoms have a mass of 39.946 amu. 83.79% have a mass of 41.941 amu, 9.50% have a mass of 42.941 amu, and 2.36% have a mass of 43.939 amu. What is the average atomic mass of atom X?
41.97 amu
42.19 amu
10.43 amu
40.04 amu
24.1% of all the isotopes of a an element have a mass of 75.23 amu, 48.7% have a mass of 74.61 amu, and 27.2% have a mass of 75.20 amu.
What is the average mass of this element?
74.92 amu
24.97 amu
75.01 amu
74.51 amu
An isotope has three forms. 30% have a mass of 4 amu, 20% have a mass of 5 amu and 50% have a mass of 3 amu. Average atomic mass will be closest to
2 amu
3 amu
4 amu
5 amu
Calculate the average atomic mass of silver.
106.38649amu
111.91896amu
107.8677amu
121
What is the atomic mass of Helium
4.0026
2.0026
4
1
What is the atomic mass of "F"
9
18
17
19
What is the atomic mass of Neon?
10
20
30
What is the atomic mass of Gold?
79
196.97
79.97
275
An element has two naturally occurring isotopes. One is 10.013 amu and is 19.9% abundant. The other is 11.01 amu and is 80.1% abundant. What is the average atomic mass? What element is it?
9.012, Beryllium
12.011, Carbon
6.941, Lithium
10.812, Boron
Compute the average atomic mass for silicon:
27.977
28.09
28.976
The average mass cannot be determined from provided information.
An element has three different isotopes. One has a mass of 35.00 amu; another has a mass of 36.00 amu; and another has a mass of 38.00 amu. What is the average atomic mass of this element?
36.33 amu
37.00 amu
12.11 amu
impossible to tell
Calcium has three different isotopes. One has a mass of 35.00 amu; another has a mass of 41.00 amu; and another has a mass of 40.00 amu. Which isotope is the most abundant of the three?
40.00 amu
41.00 amu
35.00 amu
impossible to tell
Calculate the average atomic mass of the element iron (Fe) using the following data:
[Isotope / % abundance]
[Iron 54 / 6% ] [Iron 56 / 92% ] [ Iron 57 / 2% ]
53.7 amu
54.9 amu
5592.0 amu
55.9 amu
An element has two isotopes with masses of 10 amu and 12 amu. If the average atomic mass is 11 amu, what is the percentage abundance of the 12 amu isotope?
A) 50%
B) 75%
C) 25%
D) 60%
The average atomic mass of chlorine is 35.5 amu. If chlorine has two isotopes, Cl-35 and Cl-37, which isotope is more abundant?
A) Cl-35
B) Cl-37
C) Both are equally abundant
D) Cannot be determined
An element has isotopes with masses of 20 amu, 21 amu, and 22 amu. If the average atomic mass is 20.2 amu, which isotope is the least abundant?
A) 20 amu
B) 21 amu
C) 22 amu
D) Cannot be determined
Calculate the average atomic mass of an element with isotopes of masses 50 amu (5% abundance), 52 amu (90% abundance), and 53 amu (5% abundance).
A) 51.8 amu
B) 52.0 amu
C) 52.5 amu
D) 53.0 amu
Which of the following statements is true about average atomic mass?
A) It is always a whole number
B) It is the weighted average of all isotopes
C) It is the mass of the most abundant isotope
D) It is the sum of all isotopic masses
An element has three isotopes with masses 30 amu, 31 amu, and 32 amu. If the average atomic mass is 31 amu, what can be inferred about the isotopic abundances?
A) 30 amu is the most abundant
B) 31 amu is the most abundant
C) 32 amu is the most abundant
D) All isotopes are equally abundant
If an element has isotopes with masses 100 amu and 104 amu, and the average atomic mass is 102 amu, what is the ratio of the isotopic abundances?
A) 1:1
B) 1:2
C) 2:1
D) 3:1
The average atomic mass of an element is closer to the mass of one of its isotopes. What does this indicate about the isotope?
A) It is the least abundant
B) It is the most abundant
C) It has the highest mass
D) It has the lowest mass
An element has isotopes with masses 40 amu and 44 amu. If the average atomic mass is 42 amu, what is the percentage abundance of the 40 amu isotope?
A) 25%
B) 50%
C) 75%
D) 20%
Which of the following best describes the concept of average atomic mass?
A) The mass of the most stable isotope
B) The mass of the isotope with the highest atomic number
C) The weighted average of all naturally occurring isotopes
D) The sum of the masses of all isotopes
An element has isotopes with masses 60 amu and 62 amu. If the average atomic mass is 61 amu, what can be inferred about the isotopic abundances?
A) 60 amu is more abundant
B) 62 amu is more abundant
C) Both isotopes are equally abundant
D) Cannot be determined
If an element has isotopes with masses 70 amu and 75 amu, and the average atomic mass is 72 amu, what is the percentage abundance of the 75 amu isotope?
A) 40%
B) 60%
C) 20%
D) 80%
