2.1.1 - Atomic Structure & Isotopes Flashcards
What are the three subatomic particles in an atom?
The three subatomic particles are protons, neutrons, and electrons.
What is the charge and mass of a proton?
A proton has a positive charge (+1) and a mass of approximately 1 amu (atomic mass unit).
What is the charge and mass of a neutron?
A neutron has no charge (neutral) and a mass of approximately 1 amu (atomic mass unit).
What is the charge and mass of an electron?
An electron has a negative charge (-1) and a very small mass compared to protons and neutrons (approximately 1/1836 amu).
What is the atomic number of an element?
The atomic number is the number of protons in the nucleus of an atom. It defines the element.
What is the mass number of an element?
The mass number is the total number of protons and neutrons in an atom’s nucleus.
How do you calculate the number of neutrons in an atom?
The number of neutrons can be calculated using the formula:
Number of neutrons = Mass number - Atomic number
What is an isotope?
An isotope is an atom of the same element with the same number of protons but a different number of neutrons, resulting in a different mass number.
What is the electron configuration of an atom?
Electron configuration describes the arrangement of electrons in the orbitals around the nucleus of an atom.
What is the aufbau principle in electron configuration?
The aufbau principle states that electrons fill orbitals starting from the lowest energy level to the highest, with each orbital being filled before moving to the next one.
What are the four types of orbitals in atomic structure?
The four types of orbitals are s, p, d, and f orbitals.
How many electrons can each type of orbital hold?
- s orbital: 2 electrons
- p orbital: 6 electrons
- d orbital: 10 electrons
- f orbital: 14 electrons
What is the Pauli exclusion principle?
The Pauli exclusion principle states that no two electrons in an atom can have the same set of four quantum numbers. In other words, each orbital can hold at most two electrons with opposite spins.
What is the Hund’s rule?
Hund’s rule states that electrons will fill degenerate orbitals (orbitals with the same energy level) singly before pairing up, and all unpaired electrons will have the same spin.
What is the electron configuration of hydrogen (atomic number 1)?
The electron configuration of hydrogen is 1s¹, meaning it has one electron in the 1s orbital.
What is the electron configuration of oxygen (atomic number 8)?
The electron configuration of oxygen is 1s² 2s² 2p⁴.
What is the electron configuration of neon (atomic number 10)?
The electron configuration of neon is 1s² 2s² 2p⁶, meaning its outer shell is full with 8 electrons.
How is the periodic table related to electron configuration?
The periodic table is organized by atomic number and electron configuration. Elements in the same group (column) have similar electron configurations, particularly in their outermost electrons (valence electrons).
What is a quantum number?
A quantum number describes the properties of an electron, including its energy level, orbital shape, orbital orientation, and spin.
What is the principal quantum number (n)?
The principal quantum number (n) indicates the energy level or shell in which an electron resides. Higher n values correspond to electrons being farther from the nucleus.
What is the azimuthal quantum number (l)?
The azimuthal quantum number (l) determines the shape of the orbital. It can take values from 0 to n-1, with each value corresponding to a different orbital shape:
- l = 0: s orbital
- l = 1: p orbital
- l = 2: d orbital
- l = 3: f orbital
What is the magnetic quantum number (mₗ)?
The magnetic quantum number (mₗ) specifies the orientation of the orbital in space. Its values range from -l to +l.
What is the spin quantum number (mₛ)?
The spin quantum number (mₛ) represents the spin of an electron. It can have values of +1/2 or -1/2, corresponding to the two possible spin states of an electron.
How do ionization energy and electron configuration relate?
Ionization energy is the energy required to remove an electron from an atom. Atoms with a stable electron configuration (like noble gases) have higher ionization energies, while atoms with unfilled outer orbitals (like alkali metals) have lower ionization energies.
What is the noble gas configuration?
The noble gas configuration refers to an electron configuration that is the same as that of a noble gas, with a completely filled outer shell. It is especially stable and is the preferred configuration for many elements.
