Nuclear Charge and Shielding

These flashcards cover key terms and concepts related to nuclear charge, shielding, and their effects on atomic properties as discussed in the lecture.

Nuclear Charge

The total charge of the nucleus, determined by the number of protons.

Shielding

The effect of interior electrons blocking the attractive forces between the nucleus and valence electrons.

Principal Energy Levels

The major energy levels of an atom where electrons reside.

Core Electrons

Electrons that are not involved in bonding and serve to shield valence electrons from the nucleus.

Valence Electrons

Electrons in the outermost shell of an atom that are involved in chemical bonding.

Ionization Energy

The energy required to remove an electron from an atom in its gaseous state.

Atomic Radius

The distance from the nucleus of an atom to the outermost shell of electrons.

Trends Down a Group

The general behavior of atomic properties as you move down the periodic table.

Trends Across a Period

The general behavior of atomic properties as you move from left to right across a period.

Attractive Forces

The forces that pull electrons toward the nucleus.

Repulsive Forces

The forces that push electrons away from each other and the nucleus.

Higher Nuclear Charge

When an element has more protons, resulting in stronger attraction for its electrons.

Shielding Effect

The reduction in effective nuclear charge experienced by valence electrons due to core electrons.

Sodium (Na)

An alkali metal with atomic number 11.

Chlorine (Cl)

A halogen with atomic number 17.

Sulfur (S)

A non-metal with atomic number 16.

Barium (Ba)

An alkaline earth metal with atomic number 56.

Strontium (Sr)

An alkaline earth metal with atomic number 38.

Metallic Character

The level of reactivity of a metal; increases down a group and decreases across a period.

Electronegativity

The ability of an atom to attract electrons in a bond.

Fluorine (F)

The most electronegative element, with atomic number 9.

Oxygen (O)

A non-metal essential for life, with atomic number 8.

Chlorine and Sulfur

Both are in the same period but chlorine has a higher nuclear charge.

Lead (Pb)

A heavy metal with atomic number 82, found in group 14.

Tin (Sn)

A post-transition metal with atomic number 50.

Periodic Table

A tabular arrangement of elements ordered by atomic number.

Group 1 Metals

The alkali metals in the periodic table, known for their reactivity.

Group 18 Noble Gases

Inert gases that have complete valence electron shells.

Electrons in Shells

Electrons exert both attractive and repulsive forces influencing atomic properties.

Energy Levels in Atoms

The specific regions where electrons are likely to be found around the nucleus.

Ionization Energy Trends

Ionization energy generally increases across a period and decreases down a group.

Effective Nuclear Charge

The net positive charge experienced by an electron in a multi-electron atom.

Electron Shells

The orbits in which electrons reside around the nucleus.