GENERAL CHEMISTRY ACS Final EXAM LATEST 2025 WITH CORRECT
QUESTIONS AND DETAILED ANSWERS|VERIFIED ANSWERS|ALREADY
GRADED A+
atomic number = - CORRECT ANSWER-# of protons
mass number = - CORRECT ANSWER-# of protons + neutrons
the number of protons in a neutral atom will equal the - CORRECT ANSWER-# of electrons
how to find the correct number of neutrons - CORRECT ANSWER-mass number - atomic number
Forms of the same elements that differ in amount of neutrons - CORRECT ANSWER-isotopes
What particle, if lost from the nucleus, would NOT cause a change in the atomic number? -
CORRECT ANSWER-a neutron because it has no charge
When alpha particles were shot at a metal foil target, most passed through without deflections,
while others deflected at large angles. What did this suggest to Rutherford? - CORRECT
ANSWER-that the atoms of the metal were mostly empty space, while the nucleus consisted of
most of the mass which included highly condensed positive particles (which caused the
deflection).
An atom has a valence shell configuration of 1s1. To which group of elements on the periodic
table does it belong? - CORRECT ANSWER-IA
alkali metals
electromagnetic spectrum - CORRECT ANSWER-
,The greater the wavelength of a photon..? - CORRECT ANSWER-the lower its frequency
How does ionisation energy change DOWN a group - CORRECT ANSWER--Decreases
Atomic Radius increases
Increased shielding
Despite the increased nuclear charge
Make is easier to remove electrons
How does ionisation energy change UP a group - CORRECT ANSWER--Increases
Atomic Radius decreases
Decreased shielding
Despite the decrease in nuclear charge
Makes it harder to remove electrons
First Ionisation Energy Definition - CORRECT ANSWER-The energy needed to remove one mole
of electrons from one mole of gaseous atoms to form one mole of gaseous 1+ ions
How does atomic radius change across a period - CORRECT ANSWER--Decreases
increase in positive charge of nucleus
added electrons are added to the outer energy level so don't provide any shielding effects
How does ionisation energy change across a period - CORRECT ANSWER--Increases
Greater nuclear charge
little extra shielding
little extra distance
,Why is there a drop between Groups 2 and 3 for ionisation energies - CORRECT ANSWER-The
electron being removed in group 3 is now being removed from a higher energy subshell, so
requires more energy
Why is there a drop between Groups 5 and 6 for ionisation energies - CORRECT ANSWER-The
electron being removed is from a paired subshell, so due to electron electron repulsion it
requires less energy to be removed
Trends in BP and MP across periods (Metals, Covalent, Simple) - CORRECT ANSWER--Metals: MP
increases across the group as metallic bonds get stronger due to increased cation charge and
increased number of delocalised electrons.
-Giant Covalent Lattice: many strong covalent bonds. Lots of energy required to break resulting
in high MP.
-Simple Molecular Structures: MP depends on strength of London Forces. London forces are
weak and require little energy to overcome resulting in low MP. (Noble gases are individual
atoms and so experience very weak London Forces)
How does ionic bonding strength change if charge/radii are increased - CORRECT ANSWER--
Charge: increasing charge causes the strength of the bond to increase
-Radii: increasing the radius causes the strength of the bond to decrease
By how many degrees does a lone pair decrease the bond angle by - CORRECT ANSWER-2.5
2 bonding pairs, 0 lone pairs - CORRECT ANSWER-Linear
3 bonding pairs, 0 lone pairs - CORRECT ANSWER-Trigonal planar
4 bonding pairs, 0 lone pairs - CORRECT ANSWER-tetrahedral
, 5 bonding pairs, 0 lone pairs - CORRECT ANSWER-trigonal bipyramidal
6 bonding pairs, 0 lone pairs - CORRECT ANSWER-octahedral
2 bonding pairs, 1 lone pair - CORRECT ANSWER-non-linear / "bent"
3 bonding pairs, 1 lone pair - CORRECT ANSWER-trigonal pyramidal
2 bonding pairs, 2 lone pairs - CORRECT ANSWER-nonlinear / "bent"
4 bonding pairs, 2 lone pairs - CORRECT ANSWER-Square planar
Electronegativity definition - CORRECT ANSWER-The ability of an atom to attract the bonding
electrons in a covalent bond
How are London Forces formed - CORRECT ANSWER-Electrons in an atom are likely to cause
temporary/instantaneous dipoles. This dipole induces another opposite temporary dipole in a
neighbouring atom causing the two to be attracted to each other.
Which elements form hydrogen bonding - CORRECT ANSWER-Fluorine, Oxygen, Nitrogen
Why is ice less dense than water - CORRECT ANSWER-In ice, the water molecules are arranged
in a lattice structure which has a lower density than water and there is more space between the
molecules
Are ionic substances soluble in polar solvents like water? Why? - CORRECT ANSWER-Yes,
because the ions are hydrated by the water molecules which is strong enough to overcome the
solvent-solvent bonds and solute-solute bonds
QUESTIONS AND DETAILED ANSWERS|VERIFIED ANSWERS|ALREADY
GRADED A+
atomic number = - CORRECT ANSWER-# of protons
mass number = - CORRECT ANSWER-# of protons + neutrons
the number of protons in a neutral atom will equal the - CORRECT ANSWER-# of electrons
how to find the correct number of neutrons - CORRECT ANSWER-mass number - atomic number
Forms of the same elements that differ in amount of neutrons - CORRECT ANSWER-isotopes
What particle, if lost from the nucleus, would NOT cause a change in the atomic number? -
CORRECT ANSWER-a neutron because it has no charge
When alpha particles were shot at a metal foil target, most passed through without deflections,
while others deflected at large angles. What did this suggest to Rutherford? - CORRECT
ANSWER-that the atoms of the metal were mostly empty space, while the nucleus consisted of
most of the mass which included highly condensed positive particles (which caused the
deflection).
An atom has a valence shell configuration of 1s1. To which group of elements on the periodic
table does it belong? - CORRECT ANSWER-IA
alkali metals
electromagnetic spectrum - CORRECT ANSWER-
,The greater the wavelength of a photon..? - CORRECT ANSWER-the lower its frequency
How does ionisation energy change DOWN a group - CORRECT ANSWER--Decreases
Atomic Radius increases
Increased shielding
Despite the increased nuclear charge
Make is easier to remove electrons
How does ionisation energy change UP a group - CORRECT ANSWER--Increases
Atomic Radius decreases
Decreased shielding
Despite the decrease in nuclear charge
Makes it harder to remove electrons
First Ionisation Energy Definition - CORRECT ANSWER-The energy needed to remove one mole
of electrons from one mole of gaseous atoms to form one mole of gaseous 1+ ions
How does atomic radius change across a period - CORRECT ANSWER--Decreases
increase in positive charge of nucleus
added electrons are added to the outer energy level so don't provide any shielding effects
How does ionisation energy change across a period - CORRECT ANSWER--Increases
Greater nuclear charge
little extra shielding
little extra distance
,Why is there a drop between Groups 2 and 3 for ionisation energies - CORRECT ANSWER-The
electron being removed in group 3 is now being removed from a higher energy subshell, so
requires more energy
Why is there a drop between Groups 5 and 6 for ionisation energies - CORRECT ANSWER-The
electron being removed is from a paired subshell, so due to electron electron repulsion it
requires less energy to be removed
Trends in BP and MP across periods (Metals, Covalent, Simple) - CORRECT ANSWER--Metals: MP
increases across the group as metallic bonds get stronger due to increased cation charge and
increased number of delocalised electrons.
-Giant Covalent Lattice: many strong covalent bonds. Lots of energy required to break resulting
in high MP.
-Simple Molecular Structures: MP depends on strength of London Forces. London forces are
weak and require little energy to overcome resulting in low MP. (Noble gases are individual
atoms and so experience very weak London Forces)
How does ionic bonding strength change if charge/radii are increased - CORRECT ANSWER--
Charge: increasing charge causes the strength of the bond to increase
-Radii: increasing the radius causes the strength of the bond to decrease
By how many degrees does a lone pair decrease the bond angle by - CORRECT ANSWER-2.5
2 bonding pairs, 0 lone pairs - CORRECT ANSWER-Linear
3 bonding pairs, 0 lone pairs - CORRECT ANSWER-Trigonal planar
4 bonding pairs, 0 lone pairs - CORRECT ANSWER-tetrahedral
, 5 bonding pairs, 0 lone pairs - CORRECT ANSWER-trigonal bipyramidal
6 bonding pairs, 0 lone pairs - CORRECT ANSWER-octahedral
2 bonding pairs, 1 lone pair - CORRECT ANSWER-non-linear / "bent"
3 bonding pairs, 1 lone pair - CORRECT ANSWER-trigonal pyramidal
2 bonding pairs, 2 lone pairs - CORRECT ANSWER-nonlinear / "bent"
4 bonding pairs, 2 lone pairs - CORRECT ANSWER-Square planar
Electronegativity definition - CORRECT ANSWER-The ability of an atom to attract the bonding
electrons in a covalent bond
How are London Forces formed - CORRECT ANSWER-Electrons in an atom are likely to cause
temporary/instantaneous dipoles. This dipole induces another opposite temporary dipole in a
neighbouring atom causing the two to be attracted to each other.
Which elements form hydrogen bonding - CORRECT ANSWER-Fluorine, Oxygen, Nitrogen
Why is ice less dense than water - CORRECT ANSWER-In ice, the water molecules are arranged
in a lattice structure which has a lower density than water and there is more space between the
molecules
Are ionic substances soluble in polar solvents like water? Why? - CORRECT ANSWER-Yes,
because the ions are hydrated by the water molecules which is strong enough to overcome the
solvent-solvent bonds and solute-solute bonds
