H.
represents hydrogen element. under non metal classification.
for others, you'll find them under metal element classification.
First let's find out the oxidation number of Fe in K₄[Fe(CN)₆] compound.
The oxidation number of cation, K is +1. Hence, the total charge of the anion, [Fe(CN)₆] is -4. CN has charge has -1. There are 6 CN in anion. Let's assume the oxidation number of Fe is 'a'.
Sum of the oxidation numbers of each element = Charge of the compound
a + 6 x (-1) = -4
a -6 = -4
a = +2
Hence, oxidation number of Fe in [Fe(CN)₆]⁴⁻ is +2.
Now Fe has the atomic number as 26. Hence, number of electrons in Fe at ground state is 26.
Electron configuration = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s² = [Ar] 3d⁶ 4s²
When making Fe²⁺, Fe releases 2 electrons. Hence, the number of electrons in Fe²⁺ is 26 - 2 = 24.
Hence, the electron configuration of Fe²⁺ = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶
= [Ar] 3d⁶
Hence, the number of 3d electrons of Fe in K₄[Fe(CN)₆] compound is 6.
Answer:
Why? Because of electron shells. Technically, they're not fully inert. They have very low reactivity potential, and can only be forced to become reactive with difficulty.
Explanation:
All chemical reactivity is made possible through the atom's electron arrangement. Electrons basically have shelves where they live, called "levels" or "shells". Each level is farther from the nucleus than the previous one. Atoms are most stable when their outer most shell (called the valence shell) is full. Atoms with an incomplete shell will react with other atoms, in an attempt to either fill out the outer shell, or to rid itself of it's valence electrons so that that previous level becomes a full valence level. If the valence shell ils already full, the atom will not be inclined to create compounds.
The first shell can hold up to two electrons. After the first two electrons, any additional electrons have to begin a new shell. The second shell can hold eight electrons before it becomes full. Helium is the first noble gas on the periodic table, having two protons and two electrons. Because helium's outer most shell is full, it does not react with other atoms.
By comparison, look at hydrogen and oxygen. Oxygen has eight electrons. The first two electrons occupy the first shell. The remaining six go to the second shell. This leaves the second shell with two empty spaces that can potentially be filled. Meanwhile, hydrogen has one electron, with it's valence shell having an empty space for one additional electron. Two hydrogen atoms give up their single electrons to an oxygen atom, so that all three end up with stable valence levels.
By the time an atom can fill out the second electron shell on it's own (10 total electrons) you end up with neon, the second noble gas.
