Another Chemistry Question please help???

Question

Which is the electron configuration of a transition element in the ground state?

1. [Ar]4s1

2. [Ar]3d10,4s2,4p6

3. [Ar]3d10,4s1

4. [Ar]3d10,4s2,4p1

i dont understand this at all. What makes the electron configuration of a transition element different from another?

Answer 1

3. [Ar]3d10,4s1

3 series of elements ( see periodic table ) are formed by filling the 3d,4d,5d shells of electron.
Togeher these comprise the d -BLOCK elements often called as TRANSITION ELEMENTS because of their position in between the s-block and p-block elements.

Thus from Scandium till Zn (first period of transition elements) electrons are continually filled in the d- orbital
_________ _________ _________ __________ __________

Option 1 is ruled out because its an s-block element ...an alkali metal....Potassium(K)

Option 2 is ruled out because its a p-block element... octet completed... noble gas.... Krypton(Kr)

Option 3 is a transition element... Copper(Cu) ... theoretically configuration could have been [Ar]3d9,4s2 ..... this anomaly is due to energy considerations.

Option 4 is a p-block element ... incomplete p-orbital.... Gallium(Ga)

Answer 2

What is different is the order that electrons are lost is not the same as the order (der Aufbau) that they are gained.

Now transitional metals had d orbital electrons, which may or may not be involved in valence. The reason why is that even though the d electrons are gained AFTER the s orbital electrons, the s orbital electrons are lost FIRST.

So the only answers with d orbital electrons and s orbital electrons are 2, 3, and 4.

Now transitional metals do not have p orbital electrons in the current principle quantum number, so answers 2 and 4 are wrong.

That leaves 3 as the only valid answer.

The reason why there is only one electron in the 4s orbital is that one of its electrons is added to the d orbital to allow it to form what is called a "pseudo noble gas shell", which is a lower energy level. The element with that electron configuration is Copper.

When copper loses an electron to become a cation in a chemical reaction, it is the 4s orbital electron that is lost first to form Cu+. Only after that electron is lost might it also lose an electron from the d orbital to form Cu+2.

Answer 3

OK...first of all, one has to distinguish a transition metal from a d-block element. A d-block element is one whose outermost d-orbital is in the process of filling up. A transition element is one that forms at least one compound in which it has an incomplete d-orbital. This distinction means, therefore, that in the first long period, Sc and Zn are d-block elements but they are not transition elements, because Sc2+ is d0 and Zn2+ is d10.

So...in your options:
[Ar] 4s1 is a Group 1 element, specifically K
[Ar] 3d10 4s2 4p6 is a noble gas, specifically Kr
[Ar] 3d10 4s2 4p1 is a Group 3 element, specifically Ga

So that leaves [Ar] 3d10 4s1, which is Cu. Whoever designed this question meant it to be a trick question....you had to recognise [Ar] 3d10 4s1 as the rearranged ground state of [Ar] 3d9 4s2. Incidentally Cu IS a transition element because although it forms Cu+ (which is d10), it also forms Cu2+ (which is d9)

Answer 4

1) K
2) Kr
3)Cu
4)Ga

So C is the answer since Copper is a transition element

What makes the electron configuration of a transition element different from another?
Their 3d subshell can be partially filled but in this case copper has a fully filled subshell

Answer 5

use this P1 V1 / T1 = P2 V2 / T2 since T is constant, it drops out - cancels so P1 V1 = P2 V2 5.3(28) = P2 (7) P2 = 21.2