Problem 101 - Chemistry: The Central Science in SI Units, Global Edition

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 \({ }^{266}\) 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 \(\mathrm{Sg}\) in the periodic table, what element should it most closely resemble in its chemical properties?

Step-by-Step Solution

Answer

(a) In a \(^{266}\)Sg atom, there are 106 protons, 106 electrons, and 160 neutrons. (b) Based on its position in the periodic table, Seaborgium (Sg) should most closely resemble Tungsten (W) in its chemical properties.

Step 1: Find the number of protons, electrons, and neutrons in seaborgium (Sg) atom with mass number 266

To find the number of protons, electrons, and neutrons in an atom, we need to know the atomic number, the atomic mass, and the mass number of the element. For seaborgium (Sg), you can find its atomic number in the periodic table, which is 106. The number of protons is equal to the atomic number: \(106\). The number of electrons in a neutral atom is equal to the number of protons: \(106\). The number of neutrons is given by subtracting the number of protons from the mass number: \(266 - 106 = 160\).

Step 2: Identify the element in the periodic table that Sg most closely resembles in its chemical properties

Seaborgium (Sg) is in the d-block of the periodic table and belongs to Group 6. The elements in the same group share similar chemical properties because they have the same number of valence electrons in their outer shell. Other elements in Group 6 include Chromium (Cr), Molybdenum (Mo), and Tungsten (W). Based on its position in the periodic table, Seaborgium (Sg) should most closely resemble Tungsten (W) in its chemical properties. This is because Tungsten is the element in Group 6 that is closest to Seaborgium in terms of atomic number and is the heaviest stable element in the group.

Key Concepts

Atomic Number

The atomic number is a fundamental characteristic of any chemical element. It tells you the number of protons in an element's nucleus. Since protons carry a positive charge, the atomic number also equals the number of electrons orbiting the nucleus in a neutral atom. Seaborgium (Sg) has an atomic number of 106. This means it has 106 protons and, in a neutral state, 106 electrons. When you know the atomic number, you know a lot about the element's identity and its place in the periodic table.

Mass Number

The mass number of an atom is the total of protons and neutrons in its nucleus. While protons and neutrons both contribute to the atom's mass, electrons contribute very little. For seaborgium, the mass number is 266. To find the number of neutrons in seaborgium, subtract the atomic number (protons) from the mass number:

• Mass number: 266
• Atomic number (Protons): 106
• Neutrons = Mass number - Atomic number = 266 - 106 = 160

This means seaborgium has 160 neutrons. Knowing the mass number helps in understanding the isotope of the element.

Periodic Table

The periodic table is like a map for chemists. It's a structured layout that shows all known elements, ordered by their atomic number. Elements are arranged in rows (periods) and columns (groups) based on their atomic structure and properties. Seaborgium is placed in the 7th period and group 6 of the periodic table. Its placement tells us about its reactivity, size, and several other chemical characteristics. By knowing where an element fits on the periodic table, you can predict its behavior during chemical reactions.

Chemical Properties

Chemical properties define how an element will react with others. They are influenced by the element's electronic structure, particularly its valence electrons. For seaborgium, studying chemical properties directly is challenging due to its instability. However, its position in the periodic table helps chemists predict its behavior.

• Group 6 elements have similar chemical properties.
• These properties influence their usage and reaction patterns.

Seaborgium, like other group 6 elements, likely shares similar valence electron configurations, making its chemical properties comparable to those of tungsten (W), another group 6 element.

Group 6 Elements

Elements in group 6 of the periodic table share similar chemical behaviors due to their valence electrons. This group includes Chromium (Cr), Molybdenum (Mo), Tungsten (W), and Seaborgium (Sg). Seaborgium, being a part of this group, means it might have similar metallic characteristics and reactivity patterns.

• These elements tend to be transition metals with high melting points.
• They are known for hard and dense characteristics.

Group 6 elements are often used in industrial applications due to these properties. Because seaborgium is a synthetic element, it's often compared with tungsten for research due to their close resemblance in chemical properties.