AP Chemistry : Elements and Atoms
Study concepts, example questions & explanations for AP Chemistry
All AP Chemistry Resources
Example Questions
Example Question #1 : Other Atomic Concepts
What is the shorthand electron configuration for gallium?
To write out the shorthand electronic configuration for Ga, you simply write down the noble gas that that comes before 
Example Question #111 : Ap Chemistry
An electron falling to a lower energy level gives off a blue glow (λ=475nm). How much energy is emitted?
Energy is not emitted
4.184 x 10-19 J
4.184 x 10-17 J
3.14x10-40J
3.14x10-37J
4.184 x 10-19 J
E=hf, or E=hc/λ
h is Planck's constant with a value of 6.62606957 × 10-34 m2 kg / s. Converting 475nm to m gives 4.75x10-7m. c is the speed of light with 3x108m/s. Putting these variables into the second equation you get 4.174x10-19J
Example Question #112 : Ap Chemistry
The atomic number of an atom is equal to the number of __________.
neutrons
protons
electrons + neutrons
protons + neutrons
electrons
protons
The atomic number is equal to the number of protons, because no two elements have the same number of protons. It is however possible for different elements to have the same number of electrons (through the loss or gain of electrons) or neutrons (isotopes).
Example Question #1 : Help With Ionic Bonds
Sodium will react with oxygen and form an ionic compound. Which of the following is false concerning this interaction?
The electrons are not equally shared between sodium and oxygen
In this compound, oxygen is the anion while the two sodium atoms are defined as cations
The ionic compound has an overall neutral charge
Both oxygen and the two sodiums are given stable octets by creating the ionic compound
Sodium has a higher electronegativity than oxygen, causing it to give its electron to oxygen
Sodium has a higher electronegativity than oxygen, causing it to give its electron to oxygen
Electronegativity is defined as the tendency of an atom to attract an electron in a bond that it shares with another atom. Because oxygen wants to receive two elctrons, while both sodiums wish to lose one electron, oxygen has a higher electronegativity than sodium. Typically, electronegativity can be seen as increasing as you go to the top right of the periodic table. For example, fluorine has a higher electronegativity than nitrogen.
Example Question #1 : Elemental Properties And Types
What is the energy required to form a gaseous cation from a gaseous atom?
Ionization energy
Kinetic energy
Electronegativity
Free energy
Ionization energy
This is the correct definition of ionization energy. By removing an electron from an atom, a cation is produced.
Example Question #2 : Elemental Properties And Types
Why can some atoms exceed the octet rule?
They have d-orbitals where the extra electrons can go
They do not exhibit any intermolecular forces
They are very electronegative.
They are nonmetals
They have d-orbitals where the extra electrons can go
Atoms in the third period and above have d-orbitals that can hold up to 10 elecrons. This is what allows for atoms to exceed the octet rule.
Example Question #1 : Elemental Properties And Types
What properties do metallic compounds have that others lack?
Conductivity in the liquid phase
Conductivity in the solid phase
Solid at room temperature
Brittle lattice structure
Conductivity in the solid phase
Metallic compounds have unique properties due to their electron motility. In metals, electrons are able to move freely around and between atoms. In non-metals, electrons are more tightly bound to the nucleus due to increased nuclear positive charge and decreased atomic radius. The fluidity of electrons in metals allows them to conduct electric charge.
Metals are generally non-brittle. Metals are solids at room temperature and conduct electricity in the liquid phase, but they share these properties with a number of non-metal compounds as well.
Example Question #2 : Elemental Properties And Types
Why are the transition metals good conductors of electricity?
Transition metals have only partially filled valence bands. Thus, the electrons can move among the d orbitals, and this electron flow allows the transition metals to be good conductors of electricity.
Example Question #3 : Elemental Properties And Types
Which of the following does not determine the length of an element's atomic radius?
Number of neutrons
Number of valence electrons
Effective nuclear charge that electrons experience
Number of electron shells
Number of neutrons
The number of neutorns is the only thing out of the answer choices that does not impact an element's atomic radius. Since neutrons have no charge, they do not impact the attractive forces between electrons and protons.
Example Question #6 : Elemental Properties And Types
Which of the following atoms is least likely to have a full octet when it is part of a molecule?
O
Cl
C
B
B
B (boron) is one of the atoms known for making fewer than 4 covalent bonds, and therefore not filling its octet. C (carbon) always makes 4 bonds, while O (oxygen) and Cl (chloride) are also known for having full octets.
All AP Chemistry Resources
