Isotopes

Chlorine has two isotopes, $^{35}\text{Cl}$ and $^{37}\text{Cl}$. With these isotopes, how many distinct relative molecular masses can the compound with molecular formula $\text{C}_2\text{H}_3\text{Cl}_3$ have?

May/June 2016

Which statement about the isotopes of bromine is correct? They are atoms that have the same number of

May/June 2016

Atoms and ions are composed of three kinds of sub-atomic particle.

May/June 2017

The table presents information about six particles.

May/June 2017

What property is shared by $^{40}\text{Ca}$, $^{39}\text{K}$ and $^{23}\text{Na}$?

May/June 2019

The two isotopes of chlorine are $^{35}\text{Cl}$ and $^{37}\text{Cl}$. By using these isotopes together with $^{12}\text{C}$ and $^1\text{H}$, how many distinct relative molecular masses can the compound with molecular formula $\text{C}_2\text{H}_3\text{Cl}_3$ have?

May/June 2022

The chlorine isotopes $^{35}\text{Cl}$ and $^{37}\text{Cl}$ are given. If these isotopes are combined with $^{12}\text{C}$ and $^{1}\text{H}$, how many distinct relative molecular masses can the compound with molecular formula $\text{C}_2\text{H}_3\text{Cl}_3$ have?

May/June 2022

The electron, proton and neutron counts for four different particles are shown. Which of the particles are isotopes of the same element?

May/June 2023

Naturally occurring bromine has a relative atomic mass of $80$ and is made up entirely of two isotopes with relative atomic masses $79$ and $81$. What conclusion can be drawn about naturally occurring bromine from this information alone?

May/June 2023

An atom of chlorine, Z, has a nucleon number of $37$. Which row is the correct one?

May/June 2024

Which particles are isotopes belonging to the same element?

May/June 2024

An element contains two isotopes with relative isotopic masses $x$ and $x + 2$. The diagram illustrates the arrangement of atoms in a sample of this element. What is the relative atomic mass of the sample of the element?

May/June 2024

Which option gives the correct meaning of isotopes?

May/June 2025

A pure specimen of element X has a relative atomic mass of $51.8$. This sample contains three isotopes. The table gives the relative masses and percentage abundances for two of the isotopes: relative mass $50$ with abundance $40\%$; relative mass $55$ with abundance $20\%$. What is the relative mass of the third isotope?

May/June 2025

The table gives information on the two isotopes present in a sample of the element europium. What is the relative atomic mass of this europium sample?

May/June 2025

An oxygen atom has 8 electrons, 8 protons and 10 neutrons. What is the nucleon number of this atom?

Oct/Nov 2015

A student is provided with just the nucleon number of an atom. What information about the atom's structure can be inferred?

Oct/Nov 2016

A particle of a sulfur isotope has 18 neutrons and 18 electrons. What is its symbol?

Oct/Nov 2017

Which row indicates the numbers of particles in $^{34}_{16}\text{S}^{2-}$?

Oct/Nov 2018

An atom’s nucleon number is usually larger than its proton number. The gap between these two values shows the number of ......1...... in the atom. Atoms with the same proton number but different nucleon numbers are known as ......2...... . Which words would correctly fill gaps 1 and 2?

Oct/Nov 2019

Phosphorus is one of the elements in Group V of the Periodic Table.

Oct/Nov 2019

The element chlorine has two isotopes, $^{35}_{17}\text{Cl}$ and $^{37}_{17}\text{Cl}$. In the Periodic Table, chlorine is shown as $^{35.5}_{17}\text{Cl}$. Which row gives the correct percentage of each isotope in a sample of chlorine found in nature?

Oct/Nov 2022

What is the nucleon number for the uranium isotope, $^{235}_{92}\text{U}$?

Oct/Nov 2022

For the uranium isotope, $^{235}_{92}\text{U}$, what is its nucleon number?

Oct/Nov 2022

The letters X, Y and Z stand for different atoms. $^{40}_{19}\text{X}\quad ^{39}_{19}\text{Y}\quad ^{40}_{20}\text{Z}$ Which statement is true?

Oct/Nov 2023

Which of the following statements about the isotopes of bromine is correct?

Oct/Nov 2023

The formulas of two ions are shown: $^{72}_{34}X^{2-}$ and $^{74}_{34}X^{2-}$. Which statement is correct?

Oct/Nov 2024

A specimen of element Q has two isotopes. The diagram gives the relative abundances and relative masses for these isotopes. What is the relative atomic mass, $A_r$, of this Q sample?

Oct/Nov 2024

A Mars sulfur sample contains four isotopes, and Table 2.1 lists the percentage abundance for each isotope.

Oct/Nov 2025

Table 2.1 lists the percentage abundances of four isotopes in a titanium sample taken from an asteroid.

Oct/Nov 2025