Question

According to the general trend, metallic character (increases/decreases) proceeding up a group of elements in the periodic table.

Short answer

Metallic character decreases proceeding up a group.

Step-by-step solution

Understanding Metallic Character

First, recall the definition of metallic character. Metallic character refers to the tendency of an element to lose electrons and form positive ions (cations). Metals, for instance, easily lose electrons, displaying a high metallic character.

Analyzing the Group Trend

In the periodic table, groups are vertical columns. As you move up a column, the elements generally have fewer electron shells. This means the outer electrons are closer to the nucleus.

Observing Atomic Radius Influence

When the outer electrons are closer to the nucleus, attraction between the nucleus and its electrons is stronger. Stronger attraction makes it harder for an atom to lose an electron, thus reducing metallic character.

Concluding the Trend

Therefore, as you move up a group in the periodic table, the tendency of an element to lose electrons decreases. This results in the decrease of metallic character as you go up a group.

Key concepts

Periodic Table Trends

The periodic table is not just a chart with elements, but a map that illustrates the trends of various properties. Trends are specific patterns or directions that certain properties follow as you move across periods (rows) or groups (columns) of the table.

One major trend is the change in metallic character as you move through the table. Generally, metallic character increases down a group and decreases across a period from left to right. Metals, which are on the left side, like to lose electrons and form positive ions.

As you move up a group, the metallic character decreases. This is because fewer electron shells mean the outer electrons are tightly held by the nucleus, making it harder for the atom to lose them. Similarly, going from left to right across a period, as electron filling nears completing a shell, the elements are less likely to lose electrons, further reducing metallic nature.

Electron Configuration

Electron configuration describes the distribution of electrons in an atom's orbitals. This configuration determines many chemical properties of an element, including metallic character.

The electrons are arranged in various energy levels or shells, and each shell can hold a certain number of electrons. For instance, the first shell can hold up to two electrons, while the second can hold up to eight.

Elements with few electrons in their outermost shell, like those on the left side of the periodic table, can more easily lose electrons. This tendency gives them higher metallic character. Conversely, elements with nearly full outer shells have less tendency to lose electrons and thus, exhibit non-metallic properties. The electron configuration influences how tightly the electrons are held and, indirectly, the ease with which an atom can lose those electrons.

Atomic Radius

Atomic radius is the distance from the nucleus of an atom to the outer boundary of the surrounding cloud of electrons. This property affects how easily an element can lose or gain electrons, thus influencing its metallic character.

As you move down a group in the periodic table, the atomic radius increases because new electron shells are added, making the atom larger. This increase eases the loss of electrons as they are farther from the nucleus and less tightly bound.

• Moving up a group, the radius decreases due to fewer electron shells.
• The outer electrons are closer to the nucleus.
• There's stronger attraction, making electron loss difficult, which reduces metallic character.

Understanding atomic radius helps us predict how elements will react and their overall reactivity.