The valence of common elements in junior high school chemistry

Recite the valency mantra:

1-valent potassium, sodium, silver-ammonium, hydrogen, 2valent barium, calcium, magnesium, copper, mercury, zinc.

Di-triiron, di-tetracarbon, trialuminum, tetrasilicon, pentavalent phosphorus, fluorine, chlorine, bromine, iodine 1-valent.

Oxygen sulfur 2 should be remembered.

Hydroxide, nitrate (OH, NO3

1 valence, sulfate, carbonate (SO4

CO3-2 valence, the algebraic sum of the valency of each element of the compound is zero, and the valency of the elemental element is zero.

Note: Ammonium is an NH4 atomic group; ＋

2-valent iron is called "ferrous iron";

1-valent copper is called "cuprous".

S is -2 valent in the absence of oxygen, and 4 or 6 valent in combination with oxygen. The SO32 atomic cluster is called "sulfite".

In the absence of oxygen, CL is -1 valence.

To memorize the first 20 elements of the periodic table:

1.Hydrogen (h); 2.Helium (HE); 3.

Lithium (Li); 4.Beryllium (BE); 5.Boron (b); 6.

carbon (c); 7.Nitrogen (n); 8.Oxygen (O); 9.

Fluorine (f); 10.Neon (ne); 11.sodium (Na); 12.

Magnesium (mg); 13.Aluminium (AL); 14.Silicon (Si); 15.

phosphorus (p); 16.Sulfur (s); 17.chlorine (Cl); 18.

argon (ar); 19.Potassium (k); 20.Calcium (ca).

Also memorize a few commonly used:

Iron (Fe); Copper (Cu); Zinc (Zn); Mercury (Hg); Barium (Ba); Manganese (mn); Silver (AG); Platinum (pt); Lead (Pb); Tin (sn); Gold (au); iodine(i); Bromine (br).

Keeping these in mind is enough for junior high school chemistry.

There's a table in the textbook that you can memorize!

Valence formula.

The main valency of common elements.

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.

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.

Valency formula two.

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.

There is a slippery memory of it.

The regular ones are all here.

Monovalent potassium, sodium, silver chloride, silicon.

Divalent magnesium oxygen, barium, calcium zinc.

3. Aluminum, 4 silicon, 5 nitrogen and phosphorus.

Two or three irons. Two-four carbon.

Copper-mercury bivalent is the most common.

Generally memorize 20;

Symbols and valencies of commonly used elements in chemistry:

Hydrogen h +1

Carbon Zen Lee c +4

Nitrogen n +4

Oxygen o-2

Sodium na +1

Magnesium mg +2

Al-al +3

Silicon si +4

Phosphorus p-3 +5

Sulfur s-2 +4 +6

Chlorine Cl-1

Potassium k +1

Calcium finch muffled ca +2

In the study of chemistry in junior high school, valency is a must-learn knowledge point, so how to calculate valency? The following is a summary of "How to calculate the rolling valence of junior high school chemical elementalization", which is for reference only, and you are welcome to read this article.

Valency calculation

The price of the elemental chemical cavity jujube is 0. The algebraic sum of the valency of a compound is 0, which is to remember the valency of common substances and deduce the valency of other elements. For example, hydrogen is commonly +1, oxygen-2, metals are generally +1 or +2 valence, iron has +2, +3, and some common valence states of acid ions, such as -2 of sulfate ions, -1 of hydroxide ions, -1 of nitrate ions, and -2 of carbonate ions.

First, the valency of some elements with only one valence is marked, and then the most commonly used valency of a certain element, such as oxygen, whose compound can be negative divalent or negative monovalent (oxygen is negative in peroxide), and finally according to the principle of algebra sum of positive and negative valency algebra to zero (note: to bring in the corner mark to calculate), determine the valency of unknown elements or elements with more valence.

Knowledge points of valence 1, valence has positive and negative valence.

2. Oxygen is usually -2 valence.

3. Hydrogen usually shows +1 valence.

4. When metallic elements and non-metallic elements are combined, metallic elements show positive valence, and non-metallic elements show negative valence (generally speaking, the positive valence is written in the front, and the negative valence is written in the back).

5. Some elements can show different valencies in the same substance.

6. The algebraic sum of positive and negative valencies in the compound is 0.

7. The valency of an element is a property exhibited by the atoms of an element when forming a compound, therefore, in an elemental molecule, the valency of an element is 0.

Further reading: Middle School Chemistry Learning Methods

Review often and memorize more

After class, you should review in time and do your homework carefully, which is an important part of learning chemistry well. Revision can be done after class, after week, unit, chapter, and comprehensive. Methods of revision include retelling, dictation, and making connections.

Knowledge can only be firmly grasped through multiple revisions. There are many basic concepts and principles in the current junior high school chemistry textbooks, and there are more than 20 element symbols that require mastery, and there are many more. Chemical formulas and chemical equations and some other knowledge.

Most of these contents need to be memorized on the basis of understanding, and most of them are the basis for learning chemistry, and if you can't memorize them, you will find it difficult to walk in the "kingdom of chemistry".

Do experiments

Junior high school chemistry is a natural science based on experiments, and experiments are an important way and means to carry out scientific activities. In daily learning, we should not only be familiar with the experimental principles and experimental methods of each experiment, but also pay attention to the experience of the experimental process, know the scientific methods contained in the experiment, understand the areas that need to be improved in the experiment, and pay special attention to the use of substances and phenomena around the chemical experiment. In this way, we can develop chemical concepts and enrich scientific literacy in experimental learning and activities.

Recite the valency mantra:

1-valent potassium, sodium, silver-ammonium, hydrogen, 2valent barium, calcium, magnesium, copper, mercury, zinc.

23 iron, 24 carbon, 3 aluminum, 4 silicon, 5-valent phosphorus, fluorine, chlorine, bromine, iodine, 1 valent oxygen, sulfur 2 to be remembered.

Hydroxide, nitrate (OH, NO3) 1 valence, sulfate, carbonate (SO4, CO3)-2 valence, the algebraic sum of the valency of each element of the compound is zero, and the valency of the elemental element is zero.

Note: Ammonium is an NH4 atomic group; 2-valent iron is called "ferrous iron"; 1-valent copper is called "cuprous".

S is -2 valent in the absence of oxygen, and 4 or 6 valent in combination with oxygen. The SO32 atomic cluster is called "sulfite".

In the absence of oxygen, CL is -1 valence.

There's a memory of the slippery and regular ones are all here.

Monovalent potassium, sodium, silver chloride, silicon.

Divalent magnesium oxygen, barium, calcium zinc.

3. Aluminum, 4 silicon, 5 nitrogen and phosphorus.

Di- and tri-iron and two-tetra-carbon.

Copper-mercury bivalent is the most common.

Monovalent: potassium, sodium, hydrogen and silver.

Bivalent: copper, magnesium, calcium, barium, zinc.

Trialuminum, tetrasilicon, pentavalent phosphorus.

It's not hard to keep track of the change.

Di- and tri-iron and two-tetra-carbon.

246 Sulfur complete.

The regular price of the metal is set to remember.

Elemental zero price.

monovalent potassium hydrochloride sodium silver;

Divalent oxygen, calcium, barium, magnesium, zinc.

Trialuminum, tetrasilicon, pentavalent phosphorus.

Di- and tri-iron and two-tetra-carbon.

246 sulfur is the most complete.

Copper-mercury bivalent is the most common.

Hydrogen monooxygen-2 is the standard.

The unit price state is always zero.

Hydroxide minus mononitrate.

Negative disulfate carbonate.

Negative three only have phosphate groups.

The positive price is ammonium.

Haven't you learned to slip the tongue? 1-valent potassium potassium hydrochloride sodium silver; 2-valent oxygen, calcium, barium, magnesium, zinc; 2,3 iron; 2,4 carbon; 2, 4, 6 sulfur are all complete. (Metals are all positive valence, non-metals are analyzed in terms of specific chemical formulas, in which hydrogen is mostly positive monovalent, oxygen is mostly negative bivalent, and chlorine is mostly negative monovalent) There are also some commonly used acid radicals:

Sulfate negative bivalent, sulfite negative bivalent, carbonate negative bivalent, nitrate negative bivalent These are the most commonly used. If you want to memorize the valency, it is recommended to be more chemical formulas, and then analyze the valency of each element, and you will slowly remember it after more analysis, so work hard.

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

Calcium, magnesium, barium, zinc positive bivalent.

Aluminum is three, silicon is four.

Copper has a positive one positive and two prices.

Iron has two positive and three valents.

Oxygen is minus bivalent.

Mercury is positive bivalent.

Both chlorochlorobromide and iodine have negative monovalents.

They form compounds with metals and often have a negative monovalent.

Carbon has two positive four negative prices.

Sulfur has two prices, four positives, six negatives.

Phosphorus has three positive and five negative three valents.

Monovalent potassium, sodium, silver chloride, divalent oxygen, calcium, barium, magnesium, zinc, trialuminum, tetrasilicon, pentavalent phosphorus, di-triiron, ditetracarbon, 246 sulfur are complete, copper, mercury, bivalent are the most common, all metals are normal, the element is zero, and it will never change.

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

Calcium, magnesium, barium, zinc positive bivalent.

Aluminum is three, silicon is four.

Carbon has two positive four negative prices.

Copper has a positive one positive and two prices.

Iron has two positive and three valents.

Oxygen is minus bivalent.

Mercury is positive bivalent.

Chlorochlorobromo-iodine has a negative monovalent, and the formation of compounds with metals often shows negative monovalent (fluorine boss has no positive valence), group 6, and there are four or six minus bivalent under sulfur.

Group 5 has three penta-minus three valents under nitrogen.

Sing it with "Twinkle Twinkle Twinkle Little Star" It's more convenient to remember.

Potassium k +1

Sodium na +1

Oxygen o-2

Silver ag +1

Chlorine Cl -1, +1, +5, +7

Sulfur s-2 +4 +6

Calcium Ca: +2

Carbon C +2, +4

Magnesium mg +2

Silicon si +4

Barium be +2

Nitrogen n -3, +2, +4, +5

Zinc zn +2

Phosphorus p -3, +3, +5

Copper Cu +1, +2

Sulfate SO42--2

Iron Fe +2, +3, carbonate CO32- -2

Al-al +3

Nitrate no3--1

Manganese mn +2, +4, +6, +7

Hydroxide oh--1

Hydrogen h +1

Ammonium NH4+ +1

Fluorine f-1

Phosphate po43--3

Potassium K +1 Chlor Cl -1, +1, +5, +7 Sodium Na +1 Oxygen O-2

Silver ag +1 sulfur s -2, +4, +6

Calcium Ca +2 Carbon C +2, +4

Magnesium mg +2 silicon si +4

Barium be +2 nitrogen n -3, +2, +4, +5 zn zn +2 phosphorus p -3, +3, +5

Copper Cu +1,+2 sulfate, SO42-2 iron, Fe +2,+3, carbonate, CO32--2, aluminum, AL +3, nitrate, NO3- -1

Manganese Mn +2,+4,+6,+7 hydroxide oh- -1 hydrogen h +1 ammonium NH4+ +1

Fluorine F-1 phosphate PO43--3

Monovalent hydrochloride, potassium, sodium silver, barium oxygen, calcium, magnesium, zinc, copper, copper, iron, iron, 23, 246, sulfur, 24, 24, 24, 24, aluminum, silicon, fluorochlorobromo, iodine is negative one, positive and negative valence should be distinguished, do not forget that the elemental quality is zero.

Potassium, sodium, hydrogen and silver, n-dicalcium, magnesium, barium and zinc, mono-dicopper, mercury, di-ferric, trivalent metals, aluminum and gold, fluorochloride negative monovalent, oxygen and sulfur negative bivalent.

It's good to remember these.,It's easier to memorize.,The rest don't have to be remembered.。。。 Because most of the exams only test these, and the other valencies are too 、、、

Monovalent potassium, sodium, hydrochloride, silver, divalent barium oxyoxide, magnesium, calcium, zinc, trialuminum, gold, elemental zero.

"Triple aluminum" refers to the fact that the aluminum in the compound is +3 valence, and the metal element is only normal, and the element is 0 valence.

Monovalent hydrochloride, sodium chloride, potassium, silver ear, mercury, barium, calcium, magnesium, zinc, trivalent aluminum, tetravalent silicon, trivalent pentavalent phosphorus, bivalent iron, bivalent and tetravalent carbon.

Bivalent, tetravalent, and hexavalent sulfur.

Generally memorize 20;

Symbols and valencies of commonly used elements in chemistry: hydrogen H

1 carbon c + 4 nitrogen n + 4 oxygen.

O-2 sodium Na

1 mg + 2 aluminium Al

3 silicon Si + 4 phosphorus P

3 + 5 sulfur S2 + 4 + 6 chlorine.

Cl-1 potassium K

1 calcium Ca+2

The first 20 1h hydrogen helium requirements are required.

Lithium-beryllium-boron-carbon. Nitrogen oxygen 9f fluorohalogen element: fluorine, chlorine, bromine, iodine.

10ne neon 11na

Sodium 12 mg, magnesium 13al

Aluminum 14si silica phosphorus.

Sulfur 17cl chlorine 18ar argon potassium.

Add barium and silver will do.