Midterm

Subatomic particles

Particles that make up atoms, including electrons, protons, and neutrons.

Proton

Positively charged subatomic particle found in the nucleus of an atom.

Neutron

Neutral subatomic particle found in the nucleus of an atom.

Electron

Negatively charged subatomic particle found outside the nucleus of an atom.

Atomic number

The total number of protons in the nucleus of an atom.

Nucleus

The central core of an atom, composed of protons and neutrons.

Isotopes

Atoms of the same element that have different numbers of neutrons.

Mass number

The total number of protons and neutrons in the nucleus of an atom.

Atomic mass

The weighted average of the masses of the isotopes of an element.

Principal quantum number

Indicates the energy level of an electron in an atom.

Energy sublevel

Subdivisions within an energy level, such as s, p, d, and f orbitals.

Orbital

A region of space around the nucleus where an electron is likely to be found.

Electron cloud

The region around the nucleus where electrons are most likely to be located.

Spin

The intrinsic angular momentum of an electron, which can be either clockwise or counterclockwise.

Aufbau principle

Electrons enter orbitals of lowest energy first.

Outermost energy level

The energy level that contains the valence electrons of an atom.

Electron configuration of potassium

1s 2s 2p 3s 3p 4s

Distribution of electrons in three empty 2p atomic orbitals

One electron in each orbital.

Unpaired electrons in a sulfur atom

2

Half-filled orbitals in a bromine atom

2

Stable electron configurations

Filled energy sublevels.

Basis for exceptions to the aufbau diagram

Filled and half-filled energy sublevels are more stable than partially-filled energy sublevels.

Most stable electron configuration of the 4f energy sublevel

4f

Most stable electron configuration of outer sublevels

4d 5s

Relationship between frequency and wavelength of light

They are inversely proportional to each other.

Wavelength of an electromagnetic wave with a frequency of 60 MHz

60 MHz x 300,000,000 m/s

Light given off by an electric discharge through sodium vapor

An emission spectrum.

Emission of light from an atom

Occurs when an electron drops from a higher to a lower energy level.

Relationship between energy level changes and frequencies of atomic line spectra

Increase in energy level changes leads to an increase in frequencies of atomic line spectra.

They would be the same

Comparison of atomic emission spectra of a sodium atom on Earth and in the sun

Energy of a photon with a frequency of 4 x 10^14 Hz

3 x 10^-19 J

Frequency of a photon with an energy of 5 x 10^-19 J

8 x 10^14 Hz

Variable directly proportional to frequency

Energy

Energy differences between higher and lower energy levels of an atom

They are greater in magnitude between higher energy levels.

Quanta of light

Photons

Spectra explained by Bohr's model

Spectra of single atoms with one electron

Quantum mechanical model of the atom

Involves the probability of finding an electron in a certain position.

Heisenberg uncertainty principle

If the position of a tiny moving particle is known, the velocity of the particle cannot be exactly determined.

Determining the position of a very tiny particle

By analyzing its interactions with another particle.

Wavelike properties of electrons

Useful in writing electron configurations.

Determining the probability of finding an electron in an s orbital

By the quantum mechanical model.

Representative elements

Group A elements.

Transition metals

Group B elements.

Element in the same period as phosphorus

Nitrogen.

Period in the periodic table

Corresponds to a principal energy level.

Arrangement of the modern periodic table

In order of increasing atomic number.

Majority of the elements

Metals.

Nonmetal among Pt, V, Li, and Kr

Kr.

Poor conductor of electricity

Nonmetals.

Correct symbol, number of protons, and number of electrons for In

In, 49 protons, 49 electrons.

Atomic number

Total number of protons in the nucleus.

Electron configuration of an element with 1s2s2p3s3p

Silicon.

Electron configurations of noble gases

The highest occupied s and p sublevels are completely filled.

Elements characterized by the filling of p orbitals

Groups 3A through 8A.

Electron configuration resulting in a relatively inactive element

A filled highest occupied principal energy level.

Subatomic particle determining the properties of an element

Electron.

Transition metal among Fe, Hg, U, and Te

Hg.

Grouping containing only representative elements

Al, Mg, Li.

Electron configurations of representative elements

The highest occupied s and p sublevels are partially filled.

Group 1A and Group 7A elements

Representative elements.

Representative element among Fe, Hg, U, and Te

Te.

Change in atomic radius from top to bottom in a group

It tends to increase.

Change in atomic radius from left to right across a period

It tends to decrease.

Cause of constant shielding effect across a period

Electrons are added to different principal energy levels.

Atomic size generally

Increases as you move from top to bottom within a group.

Element in the second period with the largest atomic radius

lithium.

Increase in atomic size within a group

More shielding of the electrons in the highest occupied energy level.

Fewer electrons in the highest occupied energy level

Refers to the concept that as you move from left to right across a period in the periodic table, the ionization energy increases due to the decrease in the number of electrons in the outermost energy level.

Smallest atomic radius

Refers to the concept that bromine has the smallest atomic radius among the given elements (sulfur, chlorine, selenium, bromine).

Charge of a cation

Refers to the concept that a cation has a positive charge.

Formation of cations

Refers to the concept that cations form when an atom loses electrons.

Formation of anions

Refers to the concept that anions form when an atom gains electrons.

Metals in Groups 1A, 2A, and 3A

Refers to the concept that metals in these groups lose electrons when they form ions.

Anions and cations

Refers to the concept that anions are negatively charged ions, while cations are positively charged ions.

Correct charges for ions

Refers to the concept that the correct charges for all the ions in the set Na, Mg, Al are +1, +2, +3 respectively.

Correct charges for ions

Refers to the concept that the correct charges for all the ions in the group Li, O, S are +1, -2, -2 respectively.

Lowest electronegativity value

Refers to the concept that cesium has the lowest electronegativity value among the given elements (cesium, helium, calcium, fluorine).

Highest electronegativity value

Refers to the concept that fluorine has the highest electronegativity value among the given elements (cesium, helium, calcium, fluorine).

Smallest ionic radius

Refers to the concept that lithium has the smallest ionic radius among the given elements (Li, K, O, S).

Ionization energy

Refers to the concept that ionization energy is the energy required to remove an electron from an atom in the gaseous state.

Organization of elements into groups

Refers to the concept that chemists started organizing elements into groups due to the discovery of many new elements.

Decrease in ionization energy within a group

Refers to the concept that the decrease in ionization energy within a group is due to the increase in atomic size and fewer electrons in the highest occupied energy level.

Smallest first ionization energy

Refers to the concept that sodium has the smallest first ionization energy among the given elements (sodium, calcium, potassium, magnesium).

Lowest electronegativity

Refers to the concept that lithium has the lowest electronegativity among the given elements (lithium, carbon, bromine, fluorine).

Electronegativity

Refers to the concept that electronegativity generally increases from left to right across a period.

Electronegativities of elements on the right side of a period

Refers to the concept that the electronegativities of elements on the right side of a period tend to be higher compared to the elements on the left side.

Decrease with increasing atomic number in Group 2A

Refers to the concept that ionization energy decreases with increasing atomic number in Group 2A.

Relative size of an ion to its neutral atom

Refers to the concept that the radius of an anion is greater than the radius of its neutral atom.

Increase in ionization energy across a period

Refers to the concept that the increase in ionization energy from left to right across a period is due to an increase in the size of the nucleus and fewer electrons in the highest occupied energy level.

Changes across the second period of the periodic table

Refers to the concept that ionization energy increases, atomic radii decrease, and electronegativity increases as you move from left to right across the second period of the periodic table.

Smallest first ionization energy

Refers to the concept that boron has the smallest first ionization energy among the given elements (boron, carbon, aluminum, silicon).