Question

The first atoms of seaborgium (Sg) were identified in 1974 . The longest-lived isotope of Sg has a mass number of \(266 .\) (a) How many protons, electrons, and neutrons are in an \(^{266} \mathrm{Sg}\) atom? (b) Atoms of Sg are very unstable, and it is therefore difficult to study this element's properties. Based on the position of Sg in the periodic table, what element should it most closely resemble in its chemical properties?

Short answer

In a \(^{266}\textrm{Sg}\) atom, there are 106 protons, 106 electrons, and 160 neutrons. Seaborgium (Sg) should most closely resemble Tungsten (W) in its chemical properties due to their positions in Group 6 of the periodic table and similar electron configurations.

Step-by-step solution

Find the atomic number of Seaborgium (Sg)

The atomic number of Seaborgium (Sg) is 106.

Determine the number of protons, electrons, and neutrons in a 266Sg atom

Since the atomic number of Seaborgium is 106, it has 106 protons. In a neutral atom, the number of electrons is equal to the number of protons, so there are also 106 electrons in the atom. To find the number of neutrons, we subtract the atomic number from the mass number, which is given as 266: Number of neutrons = Mass number - Atomic number Number of neutrons = 266 - 106 Number of neutrons = 160 So, in a 266Sg atom, there are 106 protons, 106 electrons, and 160 neutrons.

Identify the element with similar chemical properties

To find the element with similar chemical properties, we look at the periodic table and identify the element in the same group as Seaborgium. Seaborgium is in Group 6 of the periodic table, which consists of elements like Chromium (Cr), Molybdenum (Mo), and Tungsten (W). The element that seaborgium should most closely resemble in its chemical properties is Tungsten (W) due to their positions in the same group and similar electron configurations.

Key concepts

Atomic Number

The atomic number is a fundamental property of an element that dictates its position in the periodic table. For seaborgium (Sg), the atomic number is 106, which means each atom of seaborgium has 106 protons in its nucleus. The atomic number also tells us the number of electrons in a neutral atom—so a seaborgium atom also has 106 electrons orbiting its nucleus. These electrons are arranged in specific shells and subshells that define the element's chemical behavior.

Understanding the atomic number is essential when it comes to identifying elements and predicting their properties. For example, in our exercise, we could determine that an atom of seaborgium has 106 electrons because its atomic number is 106. This direct correlation simplifies many concepts in chemistry and physics, making atomic number a key concept in the study of elements.

Isotopes

Isotopes are variants of a particular chemical element that differ in neutron number but have the same number of protons. Seaborgium, like all elements, has various isotopes, which have unique mass numbers but the same atomic number. The longest-lived isotope of seaborgium mentioned in the exercise is seaborgium-266, which is signified with the symbol uclear notation{^{266}Sg}. The mass number (266) is the sum of protons and neutrons. By knowing the atomic number (106), we can calculate the number of neutrons as the difference between the mass number and the atomic number.

• Number of neutrons = Mass number - Atomic number
• Number of neutrons = 266 - 106
• Number of neutrons = 160

This calculation is pivotal for comprehending the structure of a seaborgium-266 atom and helps students grasp the concept of isotopes in a practical context.

Periodic Table Group

In the periodic table, elements are arranged in a series of rows (periods) and columns (groups) primarily based on electronic structure which dictates their chemical behavior. Seaborgium is located in Group 6 of the periodic table, which it shares with elements such as chromium (Cr), molybdenum (Mo), and tungsten (W). Members of the same group typically display similar properties due to a shared outer electron configuration.

For instance, elements in Group 6 are known for forming complex compounds and having high melting points. Our discussion in the solution clarifies why we would compare seaborgium's chemical properties to those of tungsten (W), it's lighter homologue. Bringing the periodic table group into the problem can help students visualize and better understand the predictive nature of the periodic table.

Chemical Properties

The chemical properties of an element are influenced by the arrangement of electrons around its nucleus, particularly the electrons in the outermost shell. As seaborgium is an artificial element, its chemical properties are not well-known due to its instability and short half-life. However, by looking at its positioning in Group 6 of the periodic table, we infer that it likely shares characteristics with other group members, like forming compounds with high oxidation states.

While it's challenging to study seaborgium directly, predictions based on periodic trends suggest that it would behave similarly to tungsten. This inferred behavior is a great educational point, as it demonstrates the value of the periodic table in predicting the properties of even the least understood elements.

Electron Configuration

Electron configuration describes the distribution of electrons of an atom or molecule in atomic or molecular orbitals. For heavy elements like seaborgium, the electron configuration is especially complex due to the influence of relativistic effects. The expected electron configuration of seaborgium is [Rn] 5f14 6d4 7s2, closely resembling that of tungsten, which helps to predict that its chemical properties will be similar to those of tungsten.

In our solution, knowing that seaborgium falls in Group 6 helps us understand that it has six electrons in its outermost 'd' subshell. Electron configuration is an intricate topic, but central to explaining why elements in the same group have similar chemical properties. This understanding is instrumental in helping students make sense of periodic trends and chemical reactivity.