They have the same electron configuration as argon, which means they are isoelectronic with argon.
I'll try to answer the question, "If the 5th term of a geometric progression is 2, then the product of its FIRST 9 terms is --?" Given the first term is A and the ratio is r, then the progression starts out... A, Ar, Ar^2, Ar^3, Ar^4, ... So the 5th term is Ar^4, which equals 2. The series continues... Ar^5, Ar^6, Ar^7, Ar^8, ... Ar^8 is the 9th term. The product P of all 9 terms is therefore: P = A * Ar * Ar^2 *...*Ar^8 Collect all the A's P = (A^9)*(1 * r * r^2 ...* r^8) P = A^9 * r^(0+1+2+...+8) There's a formula for the sum of the first n integers (n/2)(n+1), or if you don't know just add it up. 1+2+...+8 = 36 Therefore P = A^9 * r^36 Since 36 is a multiple of 9, you can simplify: P = (Ar^4)^9 Still with me? Remember that Ar^4=2 (a given fact). So finally P = 2^9 = 512. Cute problem.
an = an-1 + d term ar-1 = 11 difference d = -11 ar = ar-1 + d = 11 - 11 = 0 The term 0 follows the term 11.
Logoff their computers at the end of the work day
there ar about 200- 100 -_200
They have the same electron configuration as argon, which means they are isoelectronic with argon.
Sodium (Na+) with 1 electron in its outer shell, chlorine (Cl-) with 1 extra electron, potassium (K+) with 1 electron removed, calcium (Ca2+) with 2 electrons removed, and argon (Ar) with a full outer shell of electrons.
Arranging in increasing size: Cl- < S2- < K+ < Ca2+. Arranging in increasing ionization energy: K+ < Ca2+ < Cl- < S2-. Electron configurations: Cl-: [Ne]3s^2 3p^6 S2-: [Ne]3s^2 3p^6 K+: [Ar]4s^1 Ca2+: [Ar]4s^2
They all have stable electron configurations, either full outer shells (Argon) or filled electron orbitals (Sodium, Chlorine, Potassium, Calcium). This stability makes them chemically unreactive or less likely to form compounds under normal conditions.
Both calcium ion (Ca2+) and argon atom (Ar) have a full outer electron shell, making them stable and unreactive. This stable electron configuration is achieved by either gaining or losing electrons to attain a full valence shell.
calcium is normally [Ar] 4s2 if it is a 2+ ion, then it has lost 2 electrons so the configuration is just [Ar]
Kr
( a + ar ) = a ( 1 + r )
No, potassium (K) in its K2+ cation form and calcium (Ca) have different electronic configurations than argon (Ar). Potassium has an electron configuration of [Ar] 4s1 and calcium has an electron configuration of [Ar] 4s2. In contrast, argon has an electron configuration of 1s2 2s2 2p6 3s2 3p6.
Cl- and Ca2+ has the electronic configuration of the noble gas, Ar, with 18 electrons.
Argon (Ar) typically forms a monatomic ion with a charge of +1.
Species that are isoelectronic with Ar (argon) have the same number of electrons as Ar, which is 18 electrons. Examples include K+ (potassium ion), Ca2+ (calcium ion), and Cl- (chloride ion).