Is there a positive 6 valency of metals, and common metal valencies?

Yes. Chromium: CRO3, K2CRO4, K2CR2O7 Molybdenum: MoO3, (NH4)2MoO4

Tungsten: WO3, Na2WO4

Uranium: Na2U2O7

Manganese: K2mnO4

Iron: K2FeO4

Osmium: H2OSO4

Platinum: PTF6

Of course, sodium ferrite, potassium dichromate, etc. are all 6-valent. There are also 8-valent cases, such as tungsten tetroxide, which can be used as a catalyst for organic reactions.

potassium K, sodium Na, silver Ag, hydrogen H, +1 valence;

Calcium, Mg, Barium, Zinc, Zn, Cu, Hg, Pb+2 valence.

Aluminum Al+3, silicon Si +4, phosphorus P+5

Iron Fe+2, +3;Carbon C+2, +4

Sulfur s double number, +4, +6

Chlorine Cl singular, +1, +3, +5, +7, nitrogen, N singular and double, +1, +2, +3, +4, +5 fluoroF, bromine br, iodine I-1; Oxygen O-2

Very easy to remember valency formulas positive monohydrochloride, sodium, potassium and silver, n-dicalcium, magnesium, barium and zinc, aluminum is positive trioxygen, copper is one-two, iron two-three, fluorochlorobromide, is negative one, manganese heptammonium root is positive, iodine is also negative one, silicon is positive, minus one nitrate hydroxide, minus disulfate carbonate.

Potassium, sodium, silver, and hydrogen are positive monovalent.

Calcium, magnesium, barium, zinc positive bivalent.

Chlorochlorobromoiodine negative monovalent.

Oxygen is negative bivalent.

One or two copper, two or three iron.

3. Aluminum, 4 silicon, 4 7 manganese.

246 sulfur 24 carbon .

The unit valence is always zero.

Monovalent hydrochloride, potassium, sodium, silver, divalent oxygen, calcium, barium, magnesium, zinc, trialuminum, tetrasilicon, pentavalent phosphorus, ditriiron, ditetranitrogen, 2345 is carbon, 246 sulfur are complete.

Potassium, sodium, silver, hydrogen +1 valence, calcium, magnesium, barium, zinc, copper, mercury, lead +2 valence.

Sodium, potassium, silver, hydrogen positive one valent, magnesium calcium, zinc, barium positive bivalent, aluminum valence positive trioxide minus two, copper one two to iron two three, sulfur minus two plus four-six, chlorine valence usually minus one, minus one nitrate hydroxide, minus disulfate carbonate.

Since you are in high school, you should have learned about the electron configuration outside the nucleus, why don't you understand?

Fe has +2 because its outermost shell, 2 electrons, is the arrangement of 3d64s2. +3 is because 1 out of 6 D electrons can be lost and become 3D5. d5 is half full, and half full is stable.

Cu has +1 because it is 3d104s1 and it is easy to lose 1 electron to reach a full stable state of d10. However, +2 valence is common, and unstable d9 is common, because the hydration energy of Cu2+ (the energy released by the combination of ions and water) is particularly large, making up for the energy required for the loss of electrons.

The valence of the subgroup elements is variable because d electrons are involved in bonding. For example, MN ranges from +2 to +7. In many cases, because of hybridization, ions do not meet the statement of 8 electron stability, so it is necessary to analyze specific problems, and this is the reason why you do not test your subfamily in the exam, because there is no strong law like the main group.

Diferric: Iron can be both positive divalent and positive trivalent, i.e., iron ions and ferrous ions. Two-four carbon:

Carbon is generally positive bivalent and positive tetravalent, such as: carbon monoxide, carbon dioxide. 246 sulfur:

Sulfur can be minus bivalent, minus tetravalent, minus hexavalent, such as Fes (at this time iron positive bivalent sulfur minus bivalent), SO2 H2SO4. The main valencies of common elements: CFO-iodine negative monovalent, positive monohydrogen silver and potassium sodium.

The minus two of oxygen are clearly recorded first, and the positive two magnesium calcium barium and zinc. The third is aluminum and four silicon, and the price will be returned below. All metals are at regular price, one or two copper to two or three iron.

Manganese is two four and six seven, carbon two four to keep in mind. The negative main of non-metal is uneven, and the negative of chlorine is positive and 157. Nitrogen and phosphorus negative three and positive five, different phosphorus three nitrogen two four.

Sulfur has minus two positive four six, and it will be cooked while remembering. Chlorochlorobromoiodine negative monovalent. N-monohydrogen silver with potassium sodium. The minus two of oxygen should be remembered first; n-dimagnesium, calcium, barium and zinc.

positive three is aluminum, positive four silicon; Let's put the price change down. Common root valence formulas: monovalent ammonium nitrate; Hydrohalide hydroxide.

permanganate chlorate; Perchlorate acetate. divalent carbonate sulfate; Manganese hydrosulfate. Suspense ammonium is the normal price; Negative three has a phosphate group.

Metal Activity Order: (Junior) Potassium, Calcium, Sodium, Magnesium, Aluminum, Zinc, Iron, Tin, Lead, Hydrogen, Copper, Mercury, Silver, Platinum. (High school) potassium, calcium, sodium, magnesium, aluminum, manganese, zinc, chromium, iron, nickel, tin, lead, hydrogen; Copper, mercury, silver, platinum.

Valence formula 2: monovalent potassium hydrochloride, sodium silver; Divalent oxygen, calcium, barium, magnesium, zinc, trialuminum, tetrasilicon, pentanitrogen, phosphorus; Two-three-iron, two-four carbon,

Suppose the metal element symbol is r and its oxide is 2 valence, so the oxide chemical formula ro is generated

First of all, to correct it, there is a slight problem with your speech:

1. It can only be said that chromium is a chromium element, or hexavalent chromium ions, and the two should not be confused.

2. Hexavalent chromium generally exists in two ions, one is Cr2O7 (2-) and the other is Cr4 (2-), and the conditions for the existence of the two are different pH.

In addition, chromium generally exists in three valence states, hexavalent chromium, trivalent chromium, and metallic chromium.

Because the toxicity of hexavalent chromium is 100 times that of trivalent chromium, and it does not precipitate after adding flake alkali, it is generally necessary to add a reducing agent to reduce oxidizing hexavalent chromium to trivalent chromium first, and then precipitate it.

I don't understand the problem you said, but you have to know one thing, if there is no redox reaction, hexavalent chromium is still hexavalent chromium.