Atomic Structure and Electronic Configuration

The central part of an atom, containing protons and neutrons.

Positively charged particles found in the nucleus of an atom.

Particles with no charge found in the nucleus of the atom.

Negatively charged particles that orbit the nucleus of an atom.

A region of space where an electron is most likely to be found.

The amount of energy needed to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous ions with a +1 charge.

As you move across a period, the first ionization energy generally increases. This is because the effective nuclear charge (attraction between the nucleus and valence electrons) increases, making it harder to remove an electron.

As you move down a group, the first ionization energy generally decreases. This is because the atomic radius increases, meaning shielding effect (the repulsion between inner electrons and the valence electron) increases, decreasing the attraction between the nucleus and the valence electron.

The force of attraction between the nucleus and the valence electrons.

The inner electrons shield the valence electrons from the positive charge of the nucleus. The more electron shells, the greater the shielding effect, making it easier to remove a valence electron.

Atoms of the same element with the same number of protons but a different number of neutrons.

They exhibit similar chemical properties because they have the same number of protons and electrons, resulting in similar chemical interactions.

They possess different physical properties due to varying numbers of neutrons, leading to differences in mass, density, and other physical interactions.

Each orbital can hold a maximum of two electrons with opposite spins, minimizing repulsion.

When filling orbitals with similar energy levels, electrons occupy them individually first, then pair up.

Completely filled or half-filled orbitals result in a more stable configuration due to reduced electron repulsion.

The energy difference between the 4s and 3d orbitals is small, allowing an electron from the 4s orbital to be promoted to the 3d orbital to achieve a half-filled or full-filled 3d configuration, resulting in greater stability.

When filling electron orbitals, the 4s orbital is filled before the 3d orbital, but when removing electrons, they are removed from the 4s orbital first.

Across a period, the number of protons increases, leading to a stronger attraction between the nucleus and electrons. This results in a smaller atomic radius.

Down a group, the number of electron shells increases, leading to a larger distance between the nucleus and electrons. This results in a larger atomic radius.

The energy required to remove one electron from a neutral atom in its gaseous state.

Elements with a completely filled or half-filled outermost electron shell have higher IE as these configurations are more stable.

The outermost electron in an atom's 3p orbital is further from the nucleus than the 3s electron, making 3p easier to remove.

Removing an electron from a half-filled 3p orbital in (P) is easier than from a paired 3p orbital in (S).

The positive charge on the nucleus increases, while the electron shells remain the same, leading to a smaller ionic radius.

Adding electrons increases the number of electron shells, leading to a larger ionic radius. The addition of electrons, however, does not affect the number of protons.

The arrangement of filling electrons in orbitals. It states that electrons fill orbitals in increasing order of energy levels. The lowest energy levels are filled first, followed by the higher levels. This helps predict the electron configurations of atoms.

The tendency for an atom to lose electrons, resulting in the formation of positively charged ions (cations). This tendency is influenced by factors such as the atom's electron configuration and its position in the periodic table.

The amount of energy required to remove one mole of electrons from one mole of gaseous atoms, resulting in the formation of one mole of unipositive ions.

The energy required to extract the second electron from a unipositive ion, forming a dipositive ion.

Subshells within an electron shell are groups of orbitals with the same energy level. They are named as s, p, d, and f, each having a specific maximum number of electrons they can hold.

An atom or molecule with an unpaired electron. They are highly reactive due to their unpaired electron.

A species with a net electrical charge, formed by gaining or losing one or more electrons.

As the positive charge on the cation increases, the number of electrons lost increases, leading to a stronger electrostatic attraction between the nucleus and the remaining outer electrons.

The strength of the electrostatic attraction between the nucleus and outer electrons determines the size of the cation. A stronger attraction pulls electrons closer to the nucleus, resulting in a smaller size.

Cations with a greater positive charge experience a stronger attraction to the electrons, resulting in a smaller ionic radius. This is because the increased attraction pulls the electrons closer to the nucleus.

Across a period (horizontal row) of the periodic table, the ionic radii of cations decrease as the positive charge increases. This is due to the increasing attraction between the nucleus and outer electrons, pulling them closer.

Down a group (vertical column) of the periodic table, the ionic radii of cations increase. This is because the number of electron shells surrounding the nucleus increases, making the outer electrons further away and the ionic radius larger.