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Elements: Isotopes
Related Topics
Wize University Chemistry Textbook > Atoms, Ions, & Isotopes
Isotopes and Atomic Weight
4 Activities
Wize University Chemistry Textbook > Atoms, Ions, & Isotopes
Atomic Structure
3 Activities
Which of the following species has an isotope with a mass number of 42, 18 electrons, and an overall charge of 2+?
Ca
2+
Ba
2+
Sr
2+
Al
2+
I don't know
Check Submission
More Isotopes and Atomic Weight Questions:
Practice: Isotopes
An atom with 6 neutrons and a mass number of 13 is an isotope of which element?
Elements: Isotopes
Bromine is a noxious fuming red liquid in its elemental form. Naturally occurring bromine has two stable isotopes
79
Br (78.918
u
) and
81
Br (80.916
u
). What are the relative abundances of these two isotopes?
Enter your answer as a percentage (ex. If the answer is 16.26%, enter 16.26 as the answer)
The natural abundance of Bromine is 79.904 g/mol
Elements: Isotopes
Bromine is a noxious fuming red liquid in its elemental form. Naturally occurring bromine has two stable isotopes
79
Br (78.918
u
) and
81
Br (80.916
u
). What are the relative abundances of these two isotopes?
Enter your answer as a percentage (ex. If the answer is 16.26%, enter 16.26 as the answer)
Elements: Isotopes
Bromine is a noxious fuming red liquid in its elemental form. Naturally occurring bromine has two stable isotopes
79
Br (78.918
u
) and
81
Br (80.916
u
). What are the relative abundances of these two isotopes?
Enter your answer as a percentage (ex. If the answer is 16.26%, enter 16.26 as the answer)
Elements: Isotopic Mass
Fe has three isotopes in relatively high abundance.
54
Fe 53.94 amu 5.8 % rel. abundance
56
Fe 55.94 amu 91.8 % rel. abundance
Practice: Isotopes
An atom with 6 neutrons and a mass number of 13 is an isotope of which element?
Mg has three isotopes.
24
Mg is the most abundant (78.70%). Calculate the percentages of the other two isotopes. The exact masses are given below:
24
Mg = 23.98504 u
25
Mg = 24.98584 u
The Atom
2.
Calculate the average mass of chlorine to two decimal places given its two isotopes: chlorine-35 (34.97 amu, 76% abundance) and chlorine-37 (36.97 amu, 24% abundance).
The Atom
Calculate the average mass of chlorine to three decimal places given its two isotopes: bromine-79 (78.918 amu, 51% abundance) and bromine-81 (80.916 amu, 49% abundance).
Elements: Isotopes and Atomic Mass
Hydrogen exists as two naturally occurring isotopes 1H (1.00782504u) (99.9885%) and deuterium, 2H. What is the atomic mass of deuterium? The atomic mass of hydrogen is 1.00794u.
Elements: Isotopes
Bromine is a noxious fuming red liquid in its elemental form. Naturally occurring bromine has two stable isotopes
79
Br (78.918
u
) and
81
Br (80.916
u
). What are the relative abundances of these two isotopes?
Enter your answer as a percentage (ex. If the answer is 16.26%, enter 16.26 as the answer)
Elements: Isotopes
Nitrogen has two naturally occurring isotopes, nitrogen-14 (14.003074008u) and nitrogen-15 (15.0001088982). What is the percent abundance of each isotope if the standard atomic weight of nitrogen is 14.0067?
Elements: Isotopes
The transition metal rhenium has two stable isotopes. The atomic mass of rhenium is 186.2 g/mol. Given that 37.1% of natural rhenium is Re-185, what is the other stable isotope?
If the abundance of
6
Li (6.015121 amu) is 7.500% and the abundance of
7
Li (7.016003 amu) is 92.500%, what is the average atomic mass?
Boron has an average atomic mass of 10.81 amu. It has 2 isotopes:
11
B (relative abundance 80 %) and
10
B (relative abundance 20 %). If
11
B has an atomic mass of 11.01 amu, how much does
10
B weigh in amu?
Chlorine has two isotopes of interest. One has an atomic mass of 34.97 amu (relative abundance 75 %), while the other make up the remaining 25 % of this element. If Cl has an average atomic mass of 35.47 amu, what is the mass of the second isotope in amu?
B has two isotopes that are available naturally in meaningful abundance.
10
B (10.01 g/mol) has a relative abundance of 20 %, while
11
B (11.01 g/mol) has a relative abundance of 80 %. If you are given a 12 g sample, how many moles of
10
B are in the sample (answer in mol)?
Elements: Isotopic Mass
Copper exists as two naturally occurring isotopes
63
Cu (62.92960) (69.17%) and
65
Cu. What is the atomic mass of
65
Cu?
Elements: Isotopic Mass
Fe has three isotopes in relatively high abundance.
54
Fe 53.94 amu 5.8 % rel. abundance
56
Fe 55.94 amu 91.8 % rel. abundance
How would you determine the number of neutrons in an atom? Let's say the element is F.
Atom: Isotopes
Selenium has a number of isotopes associated with it.
76
Se = 75.92 amu rel. abundance = 0.094
77
Se = 76.92 amu rel. abundance = 0.076
Atom: Determining the mass
What is the total mass of a C atom?
Given the following information:
"The Periodic Table", image retrieved from Chemistry 2e (https://d3bxy9euw4e147.cloudfront.net/oscms-prodcms/media/documents/Chemistry2e-OP_QCzV58S.pdf) by Flowers, P
et al.
, is licensed under CC BY.
Atom: Isotopes and Atomic Weight
An ion with a -2 charge has a mass number of 52 and contains 26 electrons. Which element is this ion? Specify the isotope as well.
Carbon is made up of two stable isotopes,
12
C and
13
C.
12
C is the most abundant form (98.93%) with
13
C making up the remaining 1.07%. The
12
C nuclei is defined as exactly 12 amu, what is the weight of the
13
C nuclei? For this problem use the precise atomic weight of carbon, 12.0107
Elements: Calculating Isotopic Abundances
There are two naturally occurring and stable isotopes of lithium,
6
Li (6.0151 amu) and
7
Li (7.0160 amu). What is the abundance of
7
Li in naturally occurring Lithium?
Atom: Calculating the Mass of One Isotope
Naturally occurring potassium contains two stable isotopes. The lighter isotope,
39
K ( 38.9637 amu) is the more abundant isotope, accounting for 93.26% of the nuclei. What is the weight of the heavier isotope,
41
K?
Boron (atomic weight 10.81) is made up of two stable isotopes,
11
B and
10
B. The boron-11 nuclei weighs 11.0093 amu and the boron-10 nuclei weighs 10.0129 amu. The percentage of
11
B and
10
B in naturally occurring boron respectively is,
How many protons does
13
C have?
An atom with 6 neutrons and a mass number of 13 is an isotope of which element?
How many electrons are there in
27
59
C
O
3
+
?
^{59}_{27}CO^{3+}?
27
59
C
O
3
+
?
More Atomic Structure Questions:
Atomic Structure
Complete the following blanks in the table. Elements can be neutral atoms or charged ions. You may use the Periodic Table provided.
Bohr model: Energy
In a Hydrogen atom, for a transition to occur from n = 3 to n = 2, would energy need to be absorbed or emitted?
The Atom
1.
Match the following definitions with the correct term.
The Atom
For germanium-73 (charge = 3+), there are
32
protons,
41
neutrons and
29
electrons.
The Atom
3.
For zinc-65 (charge = 2+), there are
30
protons,
35
neutrons and
28
electrons.
Atom: Nuclear Notation
Nuclear Notation - Practice Question
How many protons, neutrons and electrons are there in
75
As
3-
?
Answer:
There are
33
protons,
42
neutrons and
36
electrons.
Elements: Atomic vs Mass Number
An atom contains 11 protons and 12 neutrons in its nucleus. Which of the following statements is/are correct?
(i) This atom has an atomic number of 12. (ii) Its mass number is 23. (iii) This atom has 12 electrons.
Elements: Atomic Number
Each element in the periodic table is assigned a number called the atomic number. This is equal to:
How many protons (p), neutrons (n) and electrons (e) are present in
80
200
H
g
2
+
{\small _{80}^{200}Hg^{2+}}
80
200
H
g
2
+
?
Of the following, which contains the greatest amount of neutrons?
How many protons does
12
C have?
Match the subatomic particle to its mass and charge.
An element is known to have a mass number of 27.
"The Periodic Table", image retrieved from Chemistry 2e (https://d3bxy9euw4e147.cloudfront.net/oscms-prodcms/media/documents/Chemistry2e-OP_QCzV58S.pdf) by Flowers, P
et al.
, is licensed under CC BY.
Elements: Atomic Mass
What is the total mass of a CO molecule? Given the following:
"The Periodic Table", image retrieved from Chemistry 2e (https://d3bxy9euw4e147.cloudfront.net/oscms-prodcms/media/documents/Chemistry2e-OP_QCzV58S.pdf) by Flowers, P
et al.
, is licensed under CC BY.
The symbol for mass number is A)
A
. The symbol for atomic number is B)
Z
(Note: Use upper case letters)
A subatomic particle has a mass of 0.00054858 amu. Which particle is it?
Oxygen has a mass number of 16 amu. How many electrons does it have?
Definitions
Connect the term with the definition
Atom: Isotopes and Atomic Weight
An ion with a -2 charge has a mass number of 52 and contains 26 electrons. Which element is this ion? Specify the isotope as well.
Atom: Atomic Structure and Weight
1) How many protons does
12
C have?
2) How many neutrons does
57
Fe have?
3) How many protons does
13
C have?
How many protons, neutrons and electrons are in a
113
In atom?
How many protons, neutrons and electrons are in a
90
Sr atom?
How many protons, neutrons and electrons are in a
57
Fe
2+
cation?
Which of the following pairs of species are isoelectronic? (Select all that apply)
Atom: Number of Protons, Electrons, Neutrons
Number of Protons, Electrons, & Neutrons
Example:
How many protons, electrons, and neutrons does Sr
2+
have?
How many neutrons does
57
Fe have?
How many protons does
13
C have?
Atomic structure: Practice
Complete the following blanks in the table. Elements can be neutral atoms or charged ions. You may use the Periodic Table provided.
Atomic Structure: Practice
Complete the following blanks in the table. Elements can be neutral atoms or charged ions. You may use the Periodic Table provided.
CHEM 1011 (Dalhousie) - The Atom
Fill-out the table below (to input the atom/ion column, zinc-65 (charge = 2+), for example, would be inputted in the following format: Zn-65 (2+). If neutral, input: Zn-65).