Unit 2: Periodic Table Trends and Classifications Self-Assessment

Vocabulary practice flashcards covering periodic families, classification of elements, and periodic trends based on electron arrangements and coulombic attraction.

Groups (Periodic Table)

The vertical columns on the Periodic Table where the group number indicates the number of valence electrons.

Periods (Periodic Table)

The horizontal rows on the Periodic Table that indicate the number of electron shells an atom possesses.

Metals

Elements characterized by being malleable, having luster, conducting electricity, and reacting with acid (e.g., chromium, gallium).

Metalloids

Also known as semi-metals, these elements are located along the staircase on the Periodic Table and have physical properties of metals and chemical properties of non-metals.

Alkali Metals

Positioned in Group 1A with $1$ valence electron; very reactive metals such as $Li$ and $Na$.

Alkaline Earth Metals

Positioned in Group 2A with $2$ valence electrons; reactive metals that are alkaline in nature, such as $Ca$ and $Mg$.

Transition Metals

"Typical" acting metals located in the middle block of the Periodic Table, including elements such as $Fe$ and $Pd$.

Halogens

Positioned in Group 7A with $7$ valence electrons; very reactive nonmetals such as $F$, $Cl$, and $Br$.

Noble Gases

Positioned in Group 8A with $8$ valence electrons; nonreactive gases such as $Ne$ and $Ar$.

Valence Electrons

The outermost electrons that participate in chemical reactions; elements in the same group share similar chemical properties because they have the same number of valence electrons.

Nonmetals

Elements that tend to be brittle and do not react with hydrochloric acid, such as sulfur.

Coulombic Attraction

The electrostatic attraction between the nucleus and electrons, which weakens down a group due to added electron shells and increases across a period.

Atomic Radius Trend

A periodic trend that increases down a group as electron shells are added and decreases across a period as increasing coulombic attraction pulls the atom closer together.

Ionization Energy Trend

The energy required to remove an electron from an atom, which increases across a period and up a group as coulombic attraction increases.

Electronegativity

The measure of an atom's ability to attract electrons within a chemical bond (for example, higher in chlorine than calcium in $CaCl_2$, and higher in oxygen than hydrogen in $H_2O$).

Lithium ($Li$)

The alkali metal with the highest ionization energy.

Argon ($Ar$)

The element in Period 3 that possesses the smallest atomic radius.

Carbon ($C$)

The element in Group 14 (4A) that exhibits the largest electronegativity.