What is the valency of the elements????

Valence one:

Monovalent chlorochlorobromoiodide, hydrood, and potassium and sodium silver.

Divalent barium oxygen, calcium, magnesium, zinc, aluminum, trisilicon, and tetra are fixed.

It is necessary to pay attention to the price change of chlorine and nitrogen, one or two copper, mercury and three gold.

Ditetracarbon, lead, ditriiron, 246, sulfur, tri-phosphorus.

The main valency of common elements is two:

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.

All metals are regular; One or two coppers come two or three irons.

Manganese is 24 and 67; The two or four of carbon should be kept in mind.

non-metallic negative main is uneven; Chlorine is negative one positive one five seven.

Nitrogen and phosphorus minus three and plus five; Different phosphorus, three nitrogen, two or four.

Sulfur has minus two, positive, four-six; It will be cooked when you use it while memorizing it.

Valency formula three:

monovalent potassium hydrochloride sodium silver; Divalent oxygen, calcium, barium, magnesium, zinc, trialuminum, tetrasilicon, pentanitrogen phosphorus; 23 iron, 24 carbon, 24 6 sulfur are all Qi; All copper is most commonly bivalent.

Common root price 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 Table:

Junior high) 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.

Solubility of salt:

Potassium, sodium, ammonium, nitrate are soluble, hydrochloride is insoluble silver mercurous;

Sulfate is insoluble barium and lead, carbon phosphate is mostly insoluble.

Most acids are soluble and alkaline, and only potassium, sodium, ammonium, and barium are soluble.

Common element valency slips (1):

potassium, sodium, hydrogen and silver are monovalent, calcium, magnesium, zinc, barium are bivalent;

Chlorochlorobromoiodine is negative monovalent, usually oxygen is negative bivalent;

Copper is one and two aluminum, and iron has two and three;

Carbon has positive two and positive four, and sulfur has negative two positive four and positive six.

Common element valency (2):

Monovalent hydrochloride, lithium potassium, sodium silver, divalent magnesium oxide, calcium, barium, zinc, copper, mercury, 12, iron, 23, carbon, tin, lead, 24, sulfur, minus, 2, positive, 46, minus, 3 to 5, nitrogen and phosphorus, halogen negative. One, one, three, five, seven, three valents remember boron, aluminum, gold.

A few rules:1In the element, each element shows 0 price.

2.The fluorine in the compound must be -1 valence.

3.Oxygen is usually -2 valent, but when combined with fluorine, it is positive.

4.Hydrogen usually has a +1 valence.

5.The valency of noble gases is usually 0, but when combined with fluorine and oxidation, it shows positive valence, such as XEF4, XEO3, etc.

K na h ag is a positive price.

CA mg Ba ZN positive bivalent.

f cl br i minus one valence.

Usually o is minus bivalent.

cu positive one, positive two, al positive three.

FE has positive two and positive three.

Another way to determine valency is to find a familiar compound and deduce that for example, Hgo O's Eq. -2 So mercury is positive two.

Metals do not have a valence h and are negative in metal compounds and are generally positive in non-metal compounds.

The above is my note.

According to the other elements with fixed valence, the total valency is 0<> anyway

For example, in iron oxide Fe2O3, oxygen is -2 valence, and the total of three oxygen is -6 valence, so two irons must be +6 valence, which can be calculated as +3 valence, and in ferrous oxide FEO, oxygen is also -2 valence, so iron is +2 valence, remember one, the total valence is 0.

The second method.

1. The formula for finding the valency of element A in AMBN compounds: (the valency of element B and the number of atoms of B) The number of atoms of A. 2. Find the valency formula of the elements with unknown valency in multiple compounds

The algebra of the valence of the elements with known valency and the number of atoms of the element with unknown valence. After giving the formula, if you know the valency of an element, you can multiply its valency by the number of atoms of that element in its molecule. Since the valency of the valency is zero, the product of the previous valency and the number of atoms of the element is subtracted from zero and divided by the number of atoms of the other element in the molecule to obtain the valency of the other element.

The valency of the two elements is given, and the least common multiple of the absolute value of the valency is obtained. Then divide the least common multiple by the absolute valence value to find the number of atoms in the molecule. Expression of valence:

Positive and negative valency is ...... with +1, +2, +3, -1, -20 and so on should be marked directly above the element symbol.