Identifying The Element: Neutrons, Protons, And Electron Configuration

Alright, chemistry enthusiasts! Let's dive into a fascinating problem that combines our knowledge of nuclear structure and electron configuration. We've got a scenario where we know some key facts about an element's isotope, and our mission is to figure out what element it is and how its electrons are arranged. Sounds like fun, right?

So, here's the deal: We're told that in the nucleus of a certain element, the number of neutrons is 14 greater than the number of protons. We also know that the mass number of this isotope is 86. With this info, we'll become chemical detectives and reveal the identity of this element. The task at hand involves identifying the element's symbol and then defining its full electron configuration. This means figuring out how the electrons are distributed among the various energy levels and orbitals within the atom. This is all basic but fundamental knowledge for any future chemist. Let's break this down step by step to see how it all comes together.

First things first: Let's lay out the groundwork. Understanding the relationship between protons, neutrons, and the mass number is absolutely crucial. Protons, which have a positive charge, define the element's atomic number. The atomic number is what dictates the element's identity and position on the periodic table. Neutrons, which have no charge, contribute to the mass of the nucleus along with the protons. The mass number is the total count of protons and neutrons in the nucleus. In the given problem, the mass number (A) is provided as 86. Additionally, we know that the number of neutrons (N) exceeds the number of protons (Z) by 14, meaning N = Z + 14. Armed with these relationships, we are ready to solve this.

To find the element's symbol and its complete electron configuration, we need to go through the following steps. Let's make this clear for everyone, especially for all the chemistry newbies out there. First of all, we need to use the mass number (A), the number of protons (Z), and the number of neutrons (N). The mass number (A) represents the total number of protons and neutrons in the nucleus of an atom. The formula is: A = Z + N. We know the mass number is 86, so A = 86. We're also told that the number of neutrons (N) is 14 more than the number of protons (Z), which we can write as N = Z + 14. Now, by substituting N in the mass number equation, we get: 86 = Z + (Z + 14). This simplifies to 86 = 2Z + 14. Now we need to solve for Z. Subtract 14 from both sides: 86 - 14 = 2Z, which becomes 72 = 2Z. Divide both sides by 2: Z = 36. Now that we know that Z = 36, it means we have 36 protons. Since the number of protons is the atomic number, we can look up the element with an atomic number of 36 on the periodic table. And here it is: Krypton (Kr).

Deciphering the Electron Configuration of Krypton

Now that we know we're dealing with Krypton, a noble gas, we can focus on determining its electron configuration. Electron configuration describes the arrangement of electrons in an atom's energy levels and sublevels. It reveals how electrons occupy the various orbitals. The electron configuration of an atom is fundamental because it dictates its chemical properties and how it interacts with other atoms. Krypton, being in the fourth period of the periodic table, is a bit more complex compared to elements in the first or second periods due to the presence of multiple electron shells and subshells.

When we have solved the identity of the element, the next step is to write down the full electron configuration. Krypton has 36 electrons (equal to its atomic number). We'll follow the Aufbau principle, which guides us in filling the electron shells and subshells in order of increasing energy. The general form to write an electron configuration is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶. Let's break it down: The first energy level (n=1) has only one subshell, the s subshell, which can hold up to 2 electrons (1s²). The second energy level (n=2) has an s subshell (2s²) and a p subshell (2p⁶), which can hold up to 6 electrons. The third energy level (n=3) has an s subshell (3s²), a p subshell (3p⁶), and a d subshell (3d¹⁰), which can hold up to 10 electrons. The fourth energy level (n=4) has an s subshell (4s²) and a p subshell (4p⁶), which can hold up to 6 electrons. Therefore, the full electron configuration of Krypton is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶. Note that this configuration follows the order dictated by the Aufbau principle, where lower energy levels and subshells are filled first. This means that after the 4s orbital is filled, the 3d orbitals are filled before the 4p orbitals. The noble gas configuration for Krypton is a good starting point for understanding its chemical behavior. These elements are inert because their outermost electron shells are complete. Remember, this configuration is extremely stable because the outermost shell is full, and this stability makes noble gases generally unreactive.

The takeaway: This problem elegantly illustrates the interplay between nuclear structure, the periodic table, and electron configurations. By knowing a bit about an atom's nucleus and the relationship between its components, we could identify the element and understand how its electrons are arranged. Understanding these concepts forms the cornerstone of chemical understanding. It allows us to predict the behavior of elements and predict how they interact.

Conclusion: The Krypton Chronicle

So, there you have it, folks! We've successfully identified the element in question as Krypton (Kr). Furthermore, we’ve meticulously described its complete electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶. This exploration highlights the beauty of chemistry—how seemingly disparate pieces of information, like neutron excess and mass numbers, can be used to unlock the secrets of matter and electron configurations. These concepts are fundamental in chemistry, serving as the basis for understanding more complex topics. With these insights, we are well-equipped to face more intricate problems in chemistry. Keep practicing, keep learning, and keep exploring the fascinating world of atoms and molecules! And remember, the periodic table is your best friend when navigating the world of elements. Now go forth, and explore more chemical mysteries! Remember that practice makes perfect, so keep solving problems, and you'll become a chemistry pro in no time.