Atoms, elements and compounds — IGCSE Physical Science (0652) questions by topic
Atoms, elements and compounds questions cover comparing isotopes of thorium by similarity and difference in their nuclei, defining the term isotopes using copper's two stable isotopes, and reading a decay graph to find the time for a count rate to drop to a given value. State, find and identify are the command words, with find meaning reading an accurate value directly off a graph.
10 real questions from 2023 papers make up this page, worth 1 to 5 marks. Because isotope questions are marked on referring to the nucleus specifically, submitting your definitions and graph readings for instant marking flags whether you've written atoms where the nucleus was needed, before the same slip repeats across similar questions.
What examiners look for
- A recurring mistake is referring to atoms instead of the nucleus, and using same symbol or element for proton number, or relative atomic mass for mass number, neither of which was accepted.
- Examiners also note candidates taking the maximum value on a time axis and dividing by two, giving beta or gamma radiation where non-ionising radiation such as radio or infrared was needed, and thinking the number of electrons was significant to an isotope's identity.
- Strong answers used the graph to read off the time at which the count rate dropped to 400 counts per minute, at about 1.2 years.
October–November 2023, Paper 21
An isotope of sodium is represented as ²³₁₁Na. Which row represents a different isotope of sodium? electrons neutrons protons A 11 13 11 B 12 12 12 C 13 12 13 D 23 12 23
Answer this question and get it marked →The numbers of protons, neutrons and electrons in particles W, X, Y and Z are shown. particle number of protons number of neutrons number of electrons W 17 18 17 X 17 20 17 Y 17…
Answer this question and get it marked →One isotope of iodine can be written as ¹³¹₅₃I. Which row describes a different isotope of iodine? atomic number mass number A 52 131 B 52 132 C 53 131 D 53 132
Answer this question and get it marked →October–November 2023, Paper 22
An isotope of sodium is represented as ²³₁₁Na. Which row represents a different isotope of sodium? electrons neutrons protons A 11 13 11 B 12 12 12 C 13 12 13 D 23 12 23
Answer this question and get it marked →The numbers of protons, neutrons and electrons in particles W, X, Y and Z are shown. particle number of protons number of neutrons number of electrons W 17 18 17 X 17 20 17 Y 17…
Answer this question and get it marked →One isotope of iodine can be written as ¹³¹₅₃I. Which row describes a different isotope of iodine? atomic number mass number A 52 131 B 52 132 C 53 131 D 53 132
Answer this question and get it marked →October–November 2023, Paper 31
²²⁸Th and ²³⁰Th are isotopes of thorium. State one similarity and one difference in the nuclei of these two isotopes of thorium.
Answer this question and get it marked →October–November 2023, Paper 32
²²⁸Th and ²³⁰Th are isotopes of thorium. State one similarity and one difference in the nuclei of these two isotopes of thorium.
Answer this question and get it marked →October–November 2023, Paper 41
Copper has two stable isotopes, ⁶³Cu and ⁶⁵Cu. Define the term isotopes.
Answer this question and get it marked →October–November 2023, Paper 42
Copper has two stable isotopes, ⁶³Cu and ⁶⁵Cu. Define the term isotopes.
Answer this question and get it marked →