IB Chemistry SL Test Practice Guide 2025-
2026
1. element a substance that cannot be broken down into simpler substances.
2. atom smallest part of an element.
3. compound substance that contains more than one element.
4. empirical formu- this shows the simplest whole number ratio of atoms of each element in a particle
la of the substance.
5. molecular formu- shows the actual number of atoms of each element in a molecule of the substance.
la
6. structural formu- this shows the arrangement of atoms an dbonds within a molecule.
la
7. molar mass the mass of one mole of any substance.
8. relative atomic the weighted mean of all the naturally occurring isotopes of the elemtn relative to
mass carbon-12
9. concentration the amount of solute (dissolved substance) in a known volume of solution (solute
plus solvent).
10. standard solution a solution of known concentration.
11. ideal gas a gas that obeys the gas laws
12. real gases a gas that hase some attractive force between the particles and do occupy some
space so they do not exactly obey the gas laws.
13. nucleons all the collective protons and neutrons
14. mass number equal to the number of protons and neutrons in the nucleus of an atom
15. atomic number
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, IB Chemistry SL Test Practice Guide 2025-
2026
equal to the number of protons in the nucleus and to the number of electrons in
the atom
16. isotope atoms of the same element with the same number of protons but with ditterent
number of neutrons
17. mass spectrome- vaporized sample is injected, ionized by being bombarded with a beam of elec-
ter trons until one electron is shoved ott, accelerated through parallel plates where
the ion is under the influence of an electric field, deflected by a magnetic field
depending on mass and charge, and detected.
18. radioisotopes isotopes of elements whose nuclei break down spontaneously. they are used in
nuclear power generation, the sterilization of surgical instruments, crime detec-
tion, finding cracks in metals, and food preservation.
19. line spectrum each element has its own characteristic spectrum that is not continuous
20. first ionization the energy required to remove one electron from an atom in its gaseous state
energy
21. electronic config- the arrangement of electrons in an atom
uration
22. valence electrons the electrons in the highest energy level
23. group vertical columns in the periodic table that holds elements with the same number
of valence electrons
24. period horizontal rows in the periodic table that holds elements with the same number of
occupied energy shells
25. atomic radius the distance from the nucleus to the outermost electron
26. cation
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2026
1. element a substance that cannot be broken down into simpler substances.
2. atom smallest part of an element.
3. compound substance that contains more than one element.
4. empirical formu- this shows the simplest whole number ratio of atoms of each element in a particle
la of the substance.
5. molecular formu- shows the actual number of atoms of each element in a molecule of the substance.
la
6. structural formu- this shows the arrangement of atoms an dbonds within a molecule.
la
7. molar mass the mass of one mole of any substance.
8. relative atomic the weighted mean of all the naturally occurring isotopes of the elemtn relative to
mass carbon-12
9. concentration the amount of solute (dissolved substance) in a known volume of solution (solute
plus solvent).
10. standard solution a solution of known concentration.
11. ideal gas a gas that obeys the gas laws
12. real gases a gas that hase some attractive force between the particles and do occupy some
space so they do not exactly obey the gas laws.
13. nucleons all the collective protons and neutrons
14. mass number equal to the number of protons and neutrons in the nucleus of an atom
15. atomic number
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, IB Chemistry SL Test Practice Guide 2025-
2026
equal to the number of protons in the nucleus and to the number of electrons in
the atom
16. isotope atoms of the same element with the same number of protons but with ditterent
number of neutrons
17. mass spectrome- vaporized sample is injected, ionized by being bombarded with a beam of elec-
ter trons until one electron is shoved ott, accelerated through parallel plates where
the ion is under the influence of an electric field, deflected by a magnetic field
depending on mass and charge, and detected.
18. radioisotopes isotopes of elements whose nuclei break down spontaneously. they are used in
nuclear power generation, the sterilization of surgical instruments, crime detec-
tion, finding cracks in metals, and food preservation.
19. line spectrum each element has its own characteristic spectrum that is not continuous
20. first ionization the energy required to remove one electron from an atom in its gaseous state
energy
21. electronic config- the arrangement of electrons in an atom
uration
22. valence electrons the electrons in the highest energy level
23. group vertical columns in the periodic table that holds elements with the same number
of valence electrons
24. period horizontal rows in the periodic table that holds elements with the same number of
occupied energy shells
25. atomic radius the distance from the nucleus to the outermost electron
26. cation
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