SCH4U : ATOMIC THEORY ACTUAL EXAM
PAPER 2026 QUESTIONS WITH ANSWERS
GRADED A+
◍ Nuclear fission..
Answer: When protons are fired at a large nucleus at high speed, splitting it
into two smaller atoms.
◍ what did JJ Thomson discover.
Answer: electrons, by using a cathode ray tube
◍ Gold Foil.
Answer: Rutherford did this experiment using alpha particles. Deflected
electrons proved there was a small positively charged nucleus.
◍ james chadwick.
Answer: confirmed the existence of neutrons in the nucleus
◍ Hund's Rule.
Answer: Atomic orbitals/suborbitals must all half-fill (up arrow), before a
second electron can be added to the orbital/suborbital (second electron is a
down arrow).
◍ atomic number.
Answer: The number of protons in the nucleus of an atom
◍ Orbital diagram.
Answer: Sometimes called "electrons in a box" It is a diagram of orbitals
represented by boxes holding 2 electrons each organized by orbitals and
energy.
◍ Atomic orbital.
Answer: An atomic orbital is a region of space in an atom where an electron
, can be located with 90% probability.There are 4 different atomic orbitals
specified by the letters s, p d, and f.
◍ Ground state.
Answer: The ground state is when an atom has all of its electrons in the
lowest energy atomic orbitals. This is the normal state of an atom.
◍ Electron configuration.
Answer: A method to write the location of all electrons in an atom by
specifying in which atomic orbital each electron is located
◍ atomic mass unit (amu).
Answer: 1/12 the mass of a carbon-12 atom
◍ Valance electrons.
Answer: The number of electrons in the outermost shell.
◍ Isotope.
Answer: Elements with the same number of protons but different number of
neutrons (stable).
◍ f, frequency.
Answer: The number of waves of electromagnetic radiation passing a
specific point per second, units are Hertz or Hz
◍ Democritus.
Answer: Greek philosopher that first proposed the idea of a "atomos". That
was the word for a mass that cannot be divided further. This is where the
term "atom" originates.
◍ atomic number.
Answer: - number of protons in an nucleus of the atom- each element has a
unique atomic number- protons determine the identity of an element-
reported on the periodic table
◍ Mass of a single proton or neutron.
Answer: 1 Atomic mass unit (amu)
◍ Aufbau Principle.
PAPER 2026 QUESTIONS WITH ANSWERS
GRADED A+
◍ Nuclear fission..
Answer: When protons are fired at a large nucleus at high speed, splitting it
into two smaller atoms.
◍ what did JJ Thomson discover.
Answer: electrons, by using a cathode ray tube
◍ Gold Foil.
Answer: Rutherford did this experiment using alpha particles. Deflected
electrons proved there was a small positively charged nucleus.
◍ james chadwick.
Answer: confirmed the existence of neutrons in the nucleus
◍ Hund's Rule.
Answer: Atomic orbitals/suborbitals must all half-fill (up arrow), before a
second electron can be added to the orbital/suborbital (second electron is a
down arrow).
◍ atomic number.
Answer: The number of protons in the nucleus of an atom
◍ Orbital diagram.
Answer: Sometimes called "electrons in a box" It is a diagram of orbitals
represented by boxes holding 2 electrons each organized by orbitals and
energy.
◍ Atomic orbital.
Answer: An atomic orbital is a region of space in an atom where an electron
, can be located with 90% probability.There are 4 different atomic orbitals
specified by the letters s, p d, and f.
◍ Ground state.
Answer: The ground state is when an atom has all of its electrons in the
lowest energy atomic orbitals. This is the normal state of an atom.
◍ Electron configuration.
Answer: A method to write the location of all electrons in an atom by
specifying in which atomic orbital each electron is located
◍ atomic mass unit (amu).
Answer: 1/12 the mass of a carbon-12 atom
◍ Valance electrons.
Answer: The number of electrons in the outermost shell.
◍ Isotope.
Answer: Elements with the same number of protons but different number of
neutrons (stable).
◍ f, frequency.
Answer: The number of waves of electromagnetic radiation passing a
specific point per second, units are Hertz or Hz
◍ Democritus.
Answer: Greek philosopher that first proposed the idea of a "atomos". That
was the word for a mass that cannot be divided further. This is where the
term "atom" originates.
◍ atomic number.
Answer: - number of protons in an nucleus of the atom- each element has a
unique atomic number- protons determine the identity of an element-
reported on the periodic table
◍ Mass of a single proton or neutron.
Answer: 1 Atomic mass unit (amu)
◍ Aufbau Principle.
