Question

(a) Does metallic character increase, decrease, or remain unchanged as one goes from left to right across a row of the periodic table? (b) Does metallic character increase, decrease, or remain unchanged as one goes down a column of the periodic table? (c) Are the periodic trends in (a) and (b) the same as or different from those for first ionization energy?

Short answer

(a) As one goes from left to right across a row of the periodic table, metallic character decreases. (b) As one goes down a column of the periodic table, metallic character increases. (c) The periodic trends in (a) are different from those for first ionization energy, while the trends in (b) are the same as those for first ionization energy.

Step-by-step solution

Metallic character trends across a row of the periodic table

To find the trend in metallic character across a row of the periodic table, we need to consider the properties of metals and how they change as we move from left to right. Metallic character is defined as how easily an atom can lose an electron. Generally, as we move from left to right across a row in the periodic table, the elements become less metallic, and the metallic character decreases.

Metallic character trends down a column of the periodic table

To find the trend in metallic character down a column of the periodic table, we again need to consider the properties of metals and how they change as we move down a column. As we move down a column in the periodic table, the elements become more metallic, and the metallic character increases.

First ionization energy trends across a row and down a column

First ionization energy is the energy required to remove the outermost electron from an atom. As we move from left to right across a row in the periodic table, the first ionization energy generally increases. This is because the number of protons increase, making it harder to remove the outermost electron due to stronger attractive forces between the nucleus and the electrons. As we move down a column in the periodic table, the first ionization energy generally decreases, due to the increased number of energy levels, making it easier for the outermost electron to be removed.

Comparing metallic character trends to first ionization energy trends

For part (a), the metallic character decreases as we go from left to right across a row, while the first ionization energy increases. These trends are different from each other. For part (b), the metallic character increases as we go down a column, and the first ionization energy decreases. These trends are the same as each other. To summarise: (a) Metallic character decreases as one goes from left to right across a row of the periodic table. (b) Metallic character increases as one goes down a column of the periodic table. (c) The periodic trends in (a) are different from those for first ionization energy, while the trends in (b) are the same as those for first ionization energy.

Key concepts

Periodic Table Trends

The periodic table is like a map that helps us understand the chemical behavior of elements. These behaviors exhibit trends that repeat across the table. One such trend is the change in metallic character as you move in different directions.

• Across a row (from left to right): Elements become less metallic. This is because atoms increasingly hold onto their electrons tightly, due to a higher nuclear charge.


• Down a column (from top to bottom): Elements become more metallic. The additional electron shells make it easier for them to lose electrons.

Knowing these trends helps chemists predict properties of unfamiliar elements based on their placement on the table. It explains why elements in the same column, or group, have similar chemical properties.

First Ionization Energy

Ionization energy is a crucial concept in chemistry, highlighting the energy needed to remove an electron from an atom. First ionization energy specifically deals with removing the outermost electron. Understanding its trends is essential:

• Across a row: The first ionization energy generally rises. This happens because of increased positive charges in the nucleus, which stronger bind the electrons.


• Down a column: The first ionization energy generally falls. As you descend, additional inner shells shield and reduce the effective nuclear pull on the electrons, making them easier to remove.

Grasping these patterns aids in predicting how reactive an element might be. Higher ionization energy typically suggests a less reactive metal since more energy is needed to free an electron.

Metallic Properties

Metallic properties are characteristics typical of metals that influence how they interact and bond with other elements. These properties include the ability to conduct electricity, malleability, and the lustrous appearance of metals. When examining periodic table trends, we notice some consistent changes:

• Across a row: Metallic properties diminish. Elements gain more non-metallic characteristics, such as brittleness and lower conductivity.


• Down a column: Metallic properties intensify. Elements become better conductors, more malleable, and retain more distinctive metal sheen.

These trends are instrumental in materials science and engineering, helping select elements for specific uses based on anticipated metallic behavior, like choosing an appropriate metal for wiring based on its conductivity.