Chemistry Chemistry Practice Problems Solutions Library

Isotopes Solutions Library

Access 209 Isotopes video and text solutions to help you complete your homework. Need to revisit the concept? Watch our Isotopes learn videos.

Browse Solutions

209 solutions

Isotopes

Q. The naturally occurring isotopes of element X consists of the isotopes 63X, and 65X. The atomic mass of 63X is 62.9396 amu with a percent abundance...

Solved • Nov 28, 2019

Isotopes

Q. Rubidium has two isotopes, rubidium-85 and rubidium-87. The atomic weight of rubidium is 85.4678 amu. If the atomic weight of rubidium-85 is 84.911...

Solved • Nov 25, 2019

Isotopes

Q. An unknown element with atomic weight 125.8 amu has two isotopes. One isotope has an abundance of 51.97% at 125.6 amu. Find the mass of the second ...

Solved • Oct 3, 2019

Isotopes

Q. Three isotopes of A (Isotope 1: 85.91 amu, 35.12%, Isotope 2: 86.91 amu, abundance 7%, Isotope 3: 87.91 amu) would have the atomic mass of what?

Solved • Sep 18, 2019

Isotopes

Q. How many protons, neutrons and electrons does the 56Fe2+ ion have?

Solved • Sep 18, 2019

Isotopes

Q. There are two isotopes of Y, 50Y (mass 49.972 amu, abundance 24.93%), 52Y (mass 51.966 amu). The atomic mass of Y in amu is what?

Solved • Sep 18, 2019

Isotopes

Q. Pretend that a new element named Szulczewskium (Sz) has been discovered. It is found to have three naturally occurring isotopes. Use the informatio...

Solved • Sep 17, 2019

Isotopes

Q. What are the numbers of electrons, sequentially, in each of the following ions?    Ca2+, Fe2+, I-, O2-       a) 20e-, 26e-, 53e-, 8e-b) 18e-, 26e-,...

Solved • Sep 14, 2019

Isotopes

Q. Which of the following pairs represent (hypothetical) isotopes? A) A and BB) A and CC) A and DD) C and D

Solved • Sep 12, 2019

Isotopes

Q. Pretend that a new element with an atomic weight of 342.38 amu was recently discovered. This element has two isotopes, the lighter of which has a m...

Solved • Sep 12, 2019

Isotopes

Q. How many neutrons are present in an atom of neon isotope, Ne-22? (atomic # 10)

Solved • Sep 4, 2019

Isotopes

Q. If there are 128 neutrons in Pb-210, how many neutrons are found in the nucleus of Pb-206?

Solved • Sep 4, 2019

Isotopes

Q. Which of the following sets represents a pair of isotopes? 14C and 14N 206Pb and 208Pb O2 and O3 32S and 32S2-

Solved • Aug 29, 2019

Isotopes

Q. What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?

Solved • Aug 26, 2019

Isotopes

Q. What is the difference between Carbon 12, 13, and 14?

Solved • Aug 8, 2019

Isotopes

Q. A carbon-12 atom has 6 protons, 6 neutrons, and 6 electrons. How many protons does a carbon-14 atom have?

Solved • Aug 7, 2019

Isotopes

Q. Gallium consists of 2 isotopes. One of those isotopes is Ga-71 with a mass of 70.92 amu with an abundance of 39.892%. What is the mass number of th...

Solved • Aug 7, 2019

Isotopes

Q. The mass number of common krypton is 84, and its atomic number is 36. Krypton-84 has how many neutrons within each isotope?

Solved • Aug 7, 2019

Isotopes

Q. What is the average atomic mass of silicon? Given the following data, calculate the average atomic mass of silicon.isotope = Si-28amu =27.9769abund...

Solved • Aug 7, 2019

Isotopes

Q. How many electrons, protons, and neutrons does nitrogen-14 have? Is it an anion or cation?

Solved • Aug 7, 2019

Isotopes

Q. Chorline exists mainly as two isotopes 35Cl and 37Cl,a) Which is more abundant?b) How do you know?c) Compute the percentage of chlorine that is the...

Solved • Aug 5, 2019

Isotopes

Q. The two naturally occurring isotopes of bromine are 81Br (80.916 amu, 49.31%) and 79Br (78.918 amu, 50.69%). The two naturally occurring isotopes o...

Solved • Aug 5, 2019

Isotopes

Q. Which of the following water molecules exists in the greatest abundance?a. D217Ob. H218Oc. T218Od. H216Oe. D216Of. T217O

Solved • Jul 10, 2019

Isotopes

Q. The table below gives the number of protons (p) and neutrons (n) for four isotopes. (i) (ii) (iii) (iv) ...

Solved • Jan 8, 2019

Isotopes

Q. The table below gives the number of protons (p) and neutrons (n) for four isotopes.(i)(ii)(iii)(iv)p19192020n19211920Write the symbol for the isoto...

Solved • Jan 8, 2019

Isotopes

Q. Indicate the number of protons and neutrons in the following nuclei.193 Tl

Solved • Jan 8, 2019

Isotopes

Q. Indicate the number of protons and neutrons in the following nuclei.The number of protons in the nuclide 12953I

Solved • Jan 8, 2019

Isotopes

Q. A certain element has only two naturally occurring isotopes: one with 18 neutrons and the other with 20 neutrons. The element forms 12 charged ions...

Solved • Nov 26, 2018

Isotopes

Q. Write symbols for the following isotopes.Z = 58 and A = 140

Solved • Oct 25, 2018

Isotopes

Q. The radioactive isotope cesium-137 was produced in large amounts in fallout from the 1986 nuclear power-plant disaster at Chernobyl, Ukraine.Write ...

Solved • Oct 25, 2018

Isotopes

Q. Germanium has five naturally occurring isotopes: 70 Ge, 20.5%, 69.924 amu; 72 Ge, 27.4%, 71.922 amu; 73 Ge, 7.8%, 72.923 amu; 74 Ge, 36.5%, 73.921 ...

Solved • Oct 25, 2018

Isotopes

Q. Hydrogen has three isotopes (1H, 2H, and 3H), and chlorine has two isotopes (35Cl and 37Cl).Tell how many protons, neutrons, and electrons 1H35Cl c...

Solved • Oct 25, 2018

Isotopes

Q. Hydrogen has three isotopes (1H, 2H, and 3H), and chlorine has two isotopes (35Cl and 37Cl).Tell how many protons, neutrons, and electrons 2H35Cl c...

Solved • Oct 25, 2018

Isotopes

Q. Naturally occurring boron consists of two isotopes: 10B (19.9%) with an isotopic mass of 10.0129 amu and 11B (80.1%) with an isotopic mass of 11.00...

Solved • Oct 25, 2018

Isotopes

Q. Naturally occurring silver consists of two isotopes: 107Ag (51.84%) with an isotopic mass of 106.9051 amu and 109Ag (48.16%) with an isotopic mass ...

Solved • Oct 25, 2018

Isotopes

Q. Magnesium has three naturally occurring isotopes: 24 Mg (23.985 amu) with 78.99% abundance, 25 Mg (24.986 amu) with 10.00% abundance, and a third w...

Solved • Oct 25, 2018

Isotopes

Q. The isotope 3475 Se is used medically for the diagnosis of pancreatic disorders.How many protons, electrons, and neutrons does an atom of 3475 Se h...

Solved • Oct 25, 2018

Isotopes

Q. Sulfur has four naturally occurring isotopes, including 33S, 34S, and 36S. Look at the periodic table, and tell whether the fourth isotope is 32S o...

Solved • Oct 25, 2018

Isotopes

Q. Copper metal has two naturally occurring isotopes: copper-63 (69.15%; isotopic mass = 62.93) and copper-65 (30.85%; isotopic mass = 64.93). Calcula...

Solved • Oct 25, 2018

Isotopes

Q. Gallium has two naturally occurring isotopes: gallium-69 (isotopic mass = 68.926 amu) and gallium-71 (isotopic mass = 70.925 amu). The atomic weigh...

Solved • Oct 25, 2018

Isotopes

Q. The nucleus of 6Li is a powerful absorber of neutrons. It exists in the naturally occurring metal to the extent of 7.5%. In the era of nuclear dete...

Solved • Oct 25, 2018

Isotopes

Q. The explosion of an atomic bomb releases many radioactive isotopes, including strontium-90. Considering the location of strontium in the periodic t...

Solved • Oct 25, 2018

Isotopes

Q. The first atoms of seaborgium (Sg) were identified in 1974. The longest-lived isotope of Sg has a mass number of 266.How many protons, electrons, a...

Solved • Oct 25, 2018

Isotopes

Q. The element oxygen has three naturally occurring isotopes, with 8, 9, and 10 neutrons in the nucleus, respectively.Write the full chemical symbols ...

Solved • Oct 25, 2018

Isotopes

Q. One way in which Earths evolution as a planet can be understood is by measuring the amounts of certain isotopes in rocks. One quantity recently mea...

Solved • Oct 25, 2018

Isotopes

Q. One way in which Earths evolution as a planet can be understood is by measuring the amounts of certain isotopes in rocks. One quantity recently mea...

Solved • Oct 25, 2018

Isotopes

Q. What isotope is used as the standard in establishing the atomic mass scale?

Solved • Oct 25, 2018

Isotopes

Q. Complete the sentence to explain why the atomic weight of carbon is reported as 12.011 in the table of elements and the periodic table in the front...

Solved • Oct 25, 2018

Isotopes

Q. Only two isotopes of copper occur naturally, 63 Cu (atomic mass = 62.9296  amu; abundance 69.17 %) and 65 Cu (atomic mass = 64.9278  amu; abundance...

Solved • Oct 25, 2018

Isotopes

Q. Rubidium has two naturally occurring isotopes, rubidium-85 (atomic mass = 84.9118 amu; abundance = 72.15%) and rubidium-87 (atomic mass = 86.9092 a...

Solved • Oct 25, 2018

Isotopes

Q. (a) Which two of the following are isotopes of the same element: 3116X, 3115X, 3216X?What is the identity of the element whose isotopes you have se...

Solved • Oct 25, 2018

Isotopes

Q. The following diagram is a representation of 20 atoms of a fictitious element, which we will call nevadium (Nv). The red spheres are 293Nv, and the...

Solved • Oct 25, 2018

Isotopes

Q. The following diagram is a representation of 20 atoms of a fictitious element, which we will call nevadium (Nv). The red spheres are 293Nv, and the...

Solved • Oct 25, 2018

Isotopes

Q. A particular atom of chromium has a mass of 52.94 amu, whereas the atomic weight of chromium is 51.99 amu. Explain the difference in the two masses.

Solved • Oct 25, 2018

Isotopes

Q. In a naturally occurring sample, 19.8% of boron atoms have five neutrons and 80.2% have six neutrons.What is the mass number of a boron atom contai...

Solved • Oct 25, 2018

Isotopes

Q. Magnesium has three naturally occurring isotopes with masses of 23.99 amu, 24.99 amu, and 25.98 amu and natural abundances of 78.99 %, 10.00 %, and...

Solved • Oct 25, 2018

Isotopes

Q. Gallium has two naturally occurring isotopes: Ga-69 with a mass of 68.9256 amu and a natural abundance of 60.11 %, and Ga-71. Use the atomic mass o...

Solved • Oct 25, 2018

Isotopes

Q. Bromine has two naturally occurring isotopes (Br-79 and Br-81) and has an atomic mass of 79.904 amu. The mass of Br-81 is 80.9163 amu, and its natu...

Solved • Oct 25, 2018

Isotopes

Q. Lithium has two naturally occurring isotopes: Li-6 (natural abundance 7.5%) and Li-7 (natural abundance 92.5%).How many Li-6 atoms would be present...

Solved • Oct 25, 2018

Isotopes

Q. Naturally occurring magnesium has an atomic mass of 24.312 and consists of three isotopes. The major isotope is 24Mg, natural abundance 78.99%, rel...

Solved • Oct 25, 2018

Isotopes

Q. Lithium has two naturally occurring isotopes: Li-6 (natural abundance 7.5%; mass 6.0151 amu) and Li-7 (natural abundance 92.5%; mass 7.0160 amu).Wi...

Solved • Oct 25, 2018

Isotopes

Q. Silver is composed of two naturally occurring isotopes: Ag-107 (51.839%) and Ag-109. The ratio of the masses of the two isotopes is 1.0187.What is ...

Solved • Oct 25, 2018

Isotopes

Q. Below is a representation of 50 atoms of a fictitious element called westmontium (Wt). The red spheres represent Wt-296, the blue spheres Wt-297, a...

Solved • Oct 25, 2018

Isotopes

Q. Below is a representation of 50 atoms of a fictitious element called westmontium (Wt). The red spheres represent Wt-296, the blue spheres Wt-297, a...

Solved • Oct 25, 2018

Isotopes

Q. Below is a representation of 50 atoms of a fictitious element called westmontium (Wt). The red spheres represent Wt-296, the blue spheres Wt-297, a...

Solved • Oct 25, 2018

Isotopes

Q. Boron has only two naturally occurring isotopes. The mass of boron-10 is 10.01294 amu and the mass of boron-11 is 11.00931 amu .Use the atomic mas...

Solved • Oct 25, 2018

Isotopes

Q. Naturally occurring chlorine is composed of two isotopes: 75.76 % Cl-35 (mass of 34.9688 amu) and 24.24 % Cl-37(mass of 36.9659 amu). Naturally occ...

Solved • Oct 25, 2018

Isotopes

Q. The atomic mass of copper is 63.546 amu.Do any copper isotopes have a mass of 63.546 amu?

Solved • Oct 25, 2018

Isotopes

Q. An element has two naturally occurring isotopes. Isotope 1 has a mass of 120.9038 amu and a relative abundance of 57.4%, and isotope 2 has a mass o...

Solved • Oct 25, 2018

Isotopes

Q. An element has two naturally occurring isotopes. Isotope 1 has a mass of 120.9038 amu and a relative abundance of 57.4%, and isotope 2 has a mass o...

Solved • Oct 25, 2018

Isotopes

Q. An element has four naturally occurring isotopes with the masses and natural abundances given here.IsotopeMass (amu)Abundance (%)1135.907140.190021...

Solved • Oct 25, 2018

Isotopes

Q. Describe the two different notations used to specify isotopes and give an example of each.

Solved • Oct 25, 2018

Isotopes

Q. Carbon has two naturally occurring isotopes: C-12 (natural abundance is 98.93%) and C-13 (natural abundance is 1.07%).How many C-13 atoms are prese...

Solved • Oct 25, 2018

Isotopes

Q. Carbon has two naturally occurring isotopes: C-12 (natural abundance is 98.93%; mass is 12.0000 amu) and C-13 (natural abundance is 1.07%; mass is ...

Solved • Oct 25, 2018

Isotopes

Q. The element silver (Ag) has two naturally occurring isotopes: 109Ag and 107Ag with a mass of 106.905 u. Silver consists of 51.82% 107Ag and has an ...

Solved • Oct 16, 2018

Isotopes

Q. An element “X” has five major isotopes, which are listed below along with their abundances. What is the element?

Solved • Oct 16, 2018

Isotopes

Q. The isotope of an unknown element, X, has a mass number of 79. The most stable ion of this isotope has 36 electrons and has a 2- charge. Which of t...

Solved • Oct 16, 2018

Isotopes

Q. The average atomic masses of some elements may vary, depending upon the sources of their ores. Naturally occurring boron consists of two isotopes w...

Solved • Oct 16, 2018

Isotopes

Q. Variations in average atomic mass may be observed for elements obtained from different sources. Lithium provides an example of this. The isotopic c...

Solved • Oct 16, 2018

Isotopes

Q. An element has the following natural abundances and isotopic masses: 90.92% abundance with 19.99 amu, 0.26% abundance with 20.99 amu, and 8.82% abu...

Solved • Oct 16, 2018

Isotopes

Q. Write the atomic symbol  for each of the isotopes described below.d. atomic number 53, number of neutrons = 79

Solved • Oct 16, 2018

Isotopes

Q. Write the atomic symbol  for each of the isotopes described below.c. Z = 12, A = 23

Solved • Oct 16, 2018

Isotopes

Q. Write the atomic symbol  for each of the isotopes described below.a. number of protons = 27, number of neutrons = 31

Solved • Oct 16, 2018

Isotopes

Q. Write the atomic symbol  for each of the following isotopes.a. Z = 8, number of neutrons = 9

Solved • Oct 16, 2018

Isotopes

Q. Antimony has many uses, for example, in infrared devices and as part of an alloy in lead storage batteries. The element has two naturally occurring...

Solved • Oct 13, 2018

Isotopes

Q. Chlorine has two naturally occurring isotopes, 35Cl (isotopic mass = 34.9689 amu) and 37Cl (isotopic mass = 36.9659 amu). If chlorine has an atomic...

Solved • Oct 12, 2018

Isotopes

Q. Magnesium has three naturally occurring isotopes, 24Mg (isotopic mass = 23.9850 amu, abundance = 78.99%), 25Mg (isotopic mass = 24.9858 amu, abunda...

Solved • Oct 12, 2018

Isotopes

Q. Gallium has two naturally occurring isotopes, 69Ga (isotopic mass = 68.9256 amu, abundance = 60.11%) and 71Ga (isotopic mass = 70.9247 amu, abundan...

Solved • Oct 12, 2018

Isotopes

Q. Chlorine has two naturally occurring isotopes, 35Cl and 37Cl. What is the mass number of each isotope? How many protons, neutrons, and electrons ar...

Solved • Oct 11, 2018

Isotopes

Q. Argon has three naturally occurring isotopes, 36Ar, 38Ar, and 40Ar. What is the mass number of each isotope? How many protons, neutrons, and electr...

Solved • Oct 11, 2018

Isotopes

Q. Which are isotopes of each other? Check all that apply.(a) 11850X(b) 12648X(c) 12549X(d) 12252X

Solved • Oct 4, 2018

Isotopes

Q. There are two naturally occurring isotopes of rubidium. 85Rb has a mass of 84.9118 amu. 87Rb has a mass of 86.9092 amu. Determine the abundance of ...

Solved • Sep 27, 2018

Isotopes

Q. On another planet, the isotopes of titanium have the following natural abundances. What is the average atomic mass of titanium on that planet? 

Solved • Sep 26, 2018

Isotopes

Q. Suppose that a fictitious element, X, has two isotopes:  50X (59.015 amu) and 82X (62.011 amu). The lighter isotope has an abundance of 73.7%. Calc...

Solved • Sep 19, 2018

Isotopes

Q. Be sure to answer all parts.Write the appropriate symbol for each of the following isotopes: (a) Z = 19, A = 41 (b) Z = 46, A = 106 (c) Z = 52, A =...

Solved • Sep 12, 2018

Isotopes

Q. Enter your answer in the provided box.Element X has two naturally occurring isotopes, 65X (isotopic mass 64.7079 amu, abundance 57.16%) and 67X (is...

Solved • Sep 12, 2018

Isotopes

Q. Which of the following are isotopes of the following atom? 35 79X(a) 35 82X(b) 38 82X(c) 36 79X(d) 3567X

Solved • Sep 12, 2018

Isotopes

Q. On a mission to a newly discovered planet, an astronaut finds gallium abundances of 61.29 % for 69Ga and 39.71 % for 71Ga. What s the atomic mass o...

Solved • Sep 11, 2018

Isotopes

Q. Part BThe astronaut then measures the abundance of magnesium on the new planet, obtaining the following result:What is the atomic mass of magnesium...

Solved • Sep 11, 2018

Isotopes

Q. On another planet, the isotopes of titanium have the following natural abundances. What is the average atomic mass of titanium on that planet?

Solved • Sep 11, 2018