Question

The successive ionization energies for an unknown element are $I_1=896\mathrm{kJ}/\mathrm{mol}$ $I_2=1752\mathrm{kJ}/\mathrm{mol}$ $I_3=14,807\mathrm{kJ}/\mathrm{mol}$ $I_4=17,948\mathrm{kJ}/\mathrm{mol}$ To which family in the periodic table does the unknown element most likely belong?

Short answer

Based on the successive ionization energies provided, the unknown element most likely belongs to the Alkaline Earth Metals family in Group 2 of the periodic table.

Step-by-step solution

We are given 4 successive ionization energies: $I_1$ = 896 kJ/mol, $I_2$ = 1752 kJ/mol, $I_3$ = 14,807 kJ/mol, and $I_4$ = 17,948 kJ/mol. #Step 2: Analyzing the ionization energy trends#

Observe the ionization energies closely. There is a significant increase in energy when moving from $I_2$ to $I_3$. This means that after the second electron is removed, the next electron to be removed is in a more stable and lower energy level. This indicates the end of a shell or a stable configuration like a noble gas. #Step 3: Determine the family of the element#

Since the significant increase occurs after the second ionization energy, it indicates that the unknown element has 2 valence electrons. Elements with 2 valence electrons belong to the Alkaline Earth Metals family in Group 2 of the periodic table. #Step 4: Conclusion#

Based on the successive ionization energies provided, the unknown element most likely belongs to the Alkaline Earth Metals family in Group 2 of the periodic table.

Key concepts

Periodic Table Families

The periodic table organizes elements into a grid of rows and columns known as periods and groups, based on their atomic structure and properties. Each column forms a 'family' or 'group' with elements sharing similar characteristics. Families include Alkali Metals, Alkaline Earth Metals, Halogens, Noble Gases, Transition Metals, and more.

Elements within the same family tend to have a consistent number of valence electrons, which dictates their chemical reactivity. For example, all Noble Gases have eight valence electrons, making them largely unreactive. Understanding how to use the periodic table and its families is crucial for predicting the behavior of elements and their compounds.

Alkaline Earth Metals

Alkaline Earth Metals, found in Group 2 of the periodic table, are a family of elements that include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). These metals are characterized by having two valence electrons, which they can easily lose to form +2 charged ions, making them highly reactive, though less so than their neighbors in Group 1, the Alkali Metals.

Due to their reactivity, Alkaline Earth Metals are commonly found in a variety of compounds and minerals. They are essential to many biological processes and are widely used in industry—for instance, magnesium is a key component in the manufacture of aircraft and electronics.

Electron Configuration

Electron configuration refers to the distribution of electrons in an atom's orbitals, which are regions around the nucleus where electrons are likely to be found. Electrons fill orbitals starting with the lowest energy level and move to higher levels as they accommodate more electrons.

Understanding electron configuration is especially helpful to predict the chemical and physical properties of an element. For instance, elements with complete electron shells are more stable and are less likely to react with other elements. The electron configuration also aids in determining the bond formation and magnetism of an element.

Valence Electrons

Valence electrons are the electrons in the outermost shell of an atom that are available for forming bonds with other atoms. These electrons play a pivotal role in an element's chemical reactivity and are often used to determine the type and number of bonds an atom can form.

For example, elements that have one valence electron, such as the Alkali Metals, are highly reactive and tend to form +1 ions. On the other hand, elements with eight valence electrons, like Noble Gases, are quite inert. The significance of valence electrons extends to predicting molecule shapes, the polarity of molecules, and the physical properties of compounds, which are all key aspects of chemistry.