Isotopes and relative atomic mass

Chemia IBPaper 1A, maj 2026, TZ2wzorowane1 pktzamknięteśrednie (szac.)

Zadanie 1

A sample of an element was analysed in a mass spectrometer and gave the spectrum shown. Which element gave this spectrum? A. Sc B. Ti C. V D. Cr

• Materiał graficzny

Chemia IBPaper 1A, maj 2026, TZ2wzorowane1 pktzamkniętełatwe (szac.)

Zadanie 2

Bromine (A_r = 79.90) consists of two isotopes, $\ce{^{79}Br}$ and $\ce{^{81}Br}$. What is the relative abundance of $\ce{^{81}Br}$? A. 10 % B. 45 % C. 55 % D. 90 %

Chemia IBPaper 2, maj 2026, TZ3wzorowane3 pktobliczenioweśrednie (szac.)

Zadanie 3a

Silver has two stable and abundant isotopes. Its relative atomic mass is 107.87. (i) Determine the percent abundance of each isotope, showing your working. (ii) State the number of protons, neutrons and electrons in $\ce{^{109}Ag+}$.

• Tabela do uzupełnienia

Chemia IBPaper 1A, maj 2025, TZ2wzorowane1 pktzamkniętełatwe (szac.)

Zadanie 2

Which property is the same for ammonia molecules containing deuterium, ND₃, and ordinary ammonia molecules, NH₃? A. Molar mass B. Molecular geometry C. Density of the gas at STP D. Rate of diffusion

Chemia IBPaper 2, maj 2025, TZ2wzorowane3 pktobliczeniowełatwe (szac.)

Zadanie 2a

Naturally occurring gallium consists of two isotopes: 60 % of the atoms contain 38 neutrons and the remaining 40 % contain 40 neutrons. (i) Use section 7 of the data booklet to deduce the nuclear symbol of the heavier isotope. (ii) Calculate the relative…

Chemia IBPaper 2, listopad 2025, TZ3wzorowane1 pktotwartełatwe (szac.)

Zadanie 5a

Contrast the two isotopes in terms of atomic structure.

Chemia IBPaper 2, listopad 2025, TZ3wzorowane4 pktobliczenioweśrednie (szac.)

Zadanie 5b

The sample produces the following mass spectrum. (i) Explain why the three peaks around m/z 72 have different relative heights. (ii) From the sample, calculate the relative atomic mass of chlorine, giving your answer to two decimal places.

• Materiał graficzny

Chemia IBPaper 1A, specimen 2025wzorowane1 pktzamkniętełatwe (szac.)

Zadanie 2

Heavy water, $\ce{^{2}H2O}$, boils at 101.4 °C, whereas ordinary water, $\ce{^{1}H2O}$, boils at 100.0 °C at the same pressure. Which statement is correct? A. The boiling points differ because $\ce{^{2}H2O}$ molecules have a greater mass, while the chemical…

Chemia IBPaper 1, listopad 2024wzorowane1 pktzamknięteśrednie (szac.)

Zadanie 5

The mass spectrum of a sample of element X is shown. What is the relative atomic mass of X? A. 69.0 B. 69.8 C. 70.0 D. 70.2

• Materiał graficzny

Chemia IBPaper 2, listopad 2024wzorowane3 pktotwarteśrednie (szac.)

Zadanie 5e

The mass spectrum of 3-methylbutanoic acid is shown. (i) Suggest why the spectrum shows a small peak at m/z 103. (ii) Identify the fragments responsible for the peaks at m/z 87 and m/z 57. Use section 22 of the data booklet.

• Materiał graficzny

Chemia IBPaper 2, maj 2023, TZ2wzorowane3 pktobliczeniowełatwe (szac.)

Zadanie 4d

Neon has three naturally occurring isotopes, $\ce{^{20}Ne}$, $\ce{^{21}Ne}$ and $\ce{^{22}Ne}$. (i) Identify the technique used to determine the relative abundances of the isotopes of neon. A sample of neon contains 90.2 % of $\ce{^{20}Ne}$, 0.3 % of…

Chemia IBPaper 1, listopad 2023, TZ1wzorowane1 pktzamknięteśrednie (szac.)

Zadanie 4

Thallium (A_r = 204.38) consists of two stable isotopes, $\ce{^{203}Tl}$ and $\ce{^{205}Tl}$. What is the relative abundance of $\ce{^{205}Tl}$? A. 31 % B. 38 % C. 62 % D. 69 %

Chemia IBPaper 2, listopad 2023, TZ1wzorowane4 pktobliczenioweśrednie (szac.)

Zadanie 4c

Naturally occurring sulfur is a mixture of several isotopes. A sample was enriched in $\ce{^{34}_{16}S}$, giving the following composition: (i) Calculate the relative atomic mass of the enriched sample to two decimal places. (ii) The abundance of…

• Tabela do uzupełnienia

Chemia IBPaper 1, listopad 2023, TZ2wzorowane1 pktzamknięteśrednie (szac.)

Zadanie 4

Naturally occurring bromine has A_r = 79.90 and contains only the isotopes ⁷⁹Br and ⁸¹Br. What percentage of the atoms are ⁸¹Br? A. 10 % B. 45 % C. 55 % D. 90 %

Chemia IBPaper 2, maj 2022, TZ1wzorowane4 pktotwarteśrednie (szac.)

Zadanie 1e

Most oxide ions are $\ce{^{16}O^2-}$. (i) State the number of protons, neutrons and electrons in this ion. (ii) Some oxide ions are $\ce{^{18}O^2-}$. State the term that describes the relationship between $\ce{^{16}O^2-}$ and $\ce{^{18}O^2-}$. (iii) The…

Chemia IBPaper 2, maj 2022, TZ1wzorowane2 pktotwartełatwe (szac.)

Zadanie 1f

Atoms were once thought to be the smallest particles of matter, impossible to divide. Suggest two pieces of evidence that show an atom has an internal structure.

Chemia IBPaper 1, maj 2022, TZ1wzorowane1 pktzamknięteśrednie (szac.)

Zadanie 4

Bromine has two naturally occurring isotopes, $\ce{^{79}Br}$ and $\ce{^{81}Br}$. The relative atomic mass of bromine is 79.90. What is the approximate percentage abundance of $\ce{^{81}Br}$? A. 25 % B. 45 % C. 55 % D. 75 %