First, let's define isolectronic. Using prefixes, iso- means same or equal, and electronic in this case is referring to electrons. So we are essentially looking for other atoms that have the same number of electrons as argon. Using the periodic table, we should refer to the atomic number since the number of protons in a neutral atom is the same as the number of electrons. So what is Argon's atomic number? 18. This means that it has 18 electrons. Show The next aspect to this question relies on your understanding of ions. Remember - what's the definition of an ion? An atom that has lost or gained electrons. Many students get confused on whether the atom will become an ion with a positive or negative charge when it gains or loses electrons. Here's my analogy. Since electrons are negative, think about negativity in life in general. If you lose negativity in your life (get rid of negative thinking, negative friends/influences), then you become a more positive person. If you gain negativity in your life, you only become more and more negative. Thus... If an atom gains electrons, it will become a negatively charged ion. If an atom loses electrons, it will become positively charged. Look at the elements close to argon such as sulfur, chlorine, potassium, and calcium. Calcium has 20 electrons. In order to get to 18 electrons (like Argon), what would have to happen? Would it have to gain electrons to go from 20 to 18? Or would it have to lose electrons? It would have to lose 2 electrons. What happens when an atom loses 2 electrons? It becomes a +2 charge. Calcium ions with a +2 are isoelectronic with Argon. Now let's look at sulfur. Sulfur has 16 electrons. What would have to happen for sulfur to go from having 16 electrons to having 18 electrons like argon? Would it have to lose 2 electrons to go from 16 to 18? Or would it have to gain 2 electrons? It would have to gain 2 electrons. What happens when an atom gains 2 electrons? It becomes a -2 charge. Sulfur ions with a -2 charge are isoelectronic with Argon. Now you should have a better understanding to determine which elements as ions with +1 and -1 charges would be isoelectronic with argon. An ion with a +1 charge would have to lose only 1 electron to become isoelectronic with argon. That would have to be potassium. Potassium ions with a +1 charge are isoelectronic with Argon. An ion with a -1 charge would have had to gain only 1 electron to become isoelectronic with argon. That would have to be chlorine. Chlorine ions with a -1 charge are isoelectronic with Argon. Answer in summary: Ca+2, K+, Cl-, S-2
In order to continue enjoying our site, we ask that you confirm your identity as a human. Thank you very much for your cooperation.
In order to continue enjoying our site, we ask that you confirm your identity as a human. Thank you very much for your cooperation.
Please log in or register to answer this question.
Please log in or register to add a comment.
(a) Write the electronic configuration for electrically neutral2 atoms of the elements. Helium atom, hydride ion and lithium ion are all isoelectronic species: Please do not block ads on this website. Isoelectronic Configurations of Atoms and IonsConsider an atom of the Nobel Gas (Group 18 element) argon, Ar. First energy level: 2 electrons in the s subshell Second energy level: 2 electrons in the s subshell and 6 electrons in the p subshell In its simplest form, we could write the electronic configuration of an atom of argon in terms of shells (energy levels) as 2,8,8 In terms of subshells, the electronic configuration would be represented as 1s22s22p63s23p6 Argon is the ONLY element whose atoms have the ground-state electronic configuration of 1s22s22p63s23p6 But there are ions of other elements that can have the ground-state electronic configuration 1s22s22p63s23p6 Consider an atom of chlorine, Cl. Chlorine has an atomic number of 17 (Z = 17). An atom of chlorine has 17 positively charged protons in its nucleus and 17 negatively charged electrons "orbiting" the nucleus in various energy levels: First energy level: 2 electrons in the s subshell Second energy level: 2 electrons in the s subshell and 6 electrons in the p subshellIn its simplest form, we could write the electronic configuration of chlorine as 2,8,7 In terms of subshells, the electronic configuration would be represented as 1s22s22p63s23p5 Like all Group 17 (halogen) elements, atoms of chlorine can gain an electron to form an anion (negatively charged ion) with a charge of 1-. Now, let's consider what happens if this chlorine atom gains an electron to form the chloride ion.
Where will this "extra" electron go?
The electronic configuration of the chloride ion, Cl-, is 1s22s22p63s23p6. It is also possible for cations, positively charged ions, to be isoelectronic with the argon atom in its ground state. Consider an atom of potassium, K, in its ground state. Potassium has an atomic number of 19 (Z = 19). There are 19 positively charged protons in the nucleus of an atom of potassium. There are 19 negatively charged electrons "orbiting" the nucleus of a potassium atom in the ground state. First energy level: 2 electrons in the s subshell Second energy level: 2 electrons in the s subshell and 6 electrons in the p subshell Third energy level: 2 electrons in the s subshell and 6 electrons in the p subshellIn its simplest form, we could write the electronic configuration of potassium as 2,8,8,1 In terms of subshells, the electronic configuration would be represented as 1s22s22p63s23p64s1 Like all Group 1 (alkali metal) elements, potassium will readily lose an electron to form a cation with a charge of +1.
The electron that is lost will come from the highest energy level, the fourth energy level:
And we can see that the potassium ion, K+, has the same electronic configuration as the chloride ion, Cl-, and the same electronic configuration as an atom of argon, Ar. Similary, we can see that an atom of calcium, Ca, (atomic number = 20) has en electronic configuration of 1s22s22p63s23p64s2
Do you know this? Join AUS-e-TUTE! Play the game now! If we consider the possible ions of the first 20 elements of the Periodic Table, we can draw up a table summarising which of the species are isoelectronic with atoms of a Group 18 (Noble Gas) element:
Do you understand this? Join AUS-e-TUTE! Take the test now! Question : Which of the species below is NOT isoelectronic with Al3+ ? Solution: (Based on the StoPGoPS approach to problem solving.)
Can you apply this? Join AUS-e-TUTE! Take the exam now! |