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Anonymous users2024-02-07First of all, potassium, sodium, silver, and hydrogen are positive and 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.
The premise of doing this is that you must remember ......
Compounds are generally not electrical, so the charge phase + of all atoms (or clusters of atoms) is 0, and it should be kept in mind that the general atoms in the compound are usually several valences (this is to be memorized, and there is also a formula).
Potassium, sodium, silver, hydrogen (K, Na, Ag, H) +1 valence, calcium, magnesium, barium, zinc (Ca, Mg, Ba, Zn) +2 valence.
Chlorochlorobromo-iodine (F, CL, BR, I)-1 valent oxygen usually -2 valent sulfur has manganese valence.
Next, you can give it a try
hgo hg---
kmno4 mn---
naclo cl---
hclo4 cl---
There are many examples: I want to improve my chemistry scores.
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Anonymous users2024-02-06Calculation according to the valence should be observed"The sum of the valencies of the elements is equal to zero".For example, in BaCl2, the valency of Ba is +2 valence, and Cl is generally -1 valence in the compound
2*1+(-1x)=0.Find x=2(Note:.)
Usually, you can calculate it directly orally, so you don't have to be so troublesome).
Remember: the valency of the elemental substance is zero.
Writing the correct chemical formula is also a disadvantage to calculate according to the valence, but the reverse calculation is just the opposite, and the same is observed"The sum of the valencies of the elements is equal to zero".
Valence formula.
Hydrogen +1, Oxygen-2, Silver, Lithium, Sodium, Potassium +L, Zinc, Magnesium, Calcium, Barium +2, Aluminum +3, Silicon +4
Only metal or hydrogen, nitrogen, phosphorus-3, sulfur-2, chlorochlorobromide-iodine total -1
Variable price, not terrible, specific judgment"and zero".
If the element is zero, it should be remembered.
A chemical formula is a formula that uses element symbols to represent the composition of matter, and the sum of the relative atomic masses of each atom in the chemical formula is the quantity of the formula.
H2 is elemental when it is written alone, so h is +1, 2 hydrogen atoms are +2 valence, o is -2, there are 4 oxygen atoms, so o4=-8, so s=-8+2=-6
h +1s=-6
o = -2 looks.
Answer, support me.
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Anonymous users2024-02-05Valency is a type of element that manifests itself only when the elements are combined with each other. In a compound, the algebraic sum of positive and negative valency is equal to zero, which is the criterion for finding valency. Generally speaking, there are several ways to find the following:
1. Chemical formula or radical formula.
1. Find the formula for the valency of element A in AMBN compounds
The valency of element b (the number of atoms of b) the number of atoms of a.
2. Find the valency formula for the elements in the unknown valence field of multiple compounds
The algebra of the valence of the elements with known valency and the number of atoms of the element with unknown valence.
3. Judge the valency of elements (or atomic clusters) according to the number of positive and negative charges.
In the radical formula, the algebraic sum of the positive and negative valence total valence numbers is equal to the positive and negative charge numbers carried by the radical.
Second, by the element mass ratio.
1. (The relative atomic mass of element A and the valency of element B) (The relative atomic mass of element B The valency of element) = the mass ratio of element A and the mass ratio of element B.
2. The mass ratio (or percentage composition) of element A The valency of a The relative atomic mass of a = The mass ratio of element B (or percentage composition) The valency of b The relative atomic mass of B.
Third, by the mass ratio.
The valency of b is the relative atomic mass ratio of a) (the valency of a is the relative atomic mass ratio of b) = the mass ratio of element a and the mass ratio of element b.
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Anonymous users2024-02-041. The most basic valence is the first step, and it must be mastered.
For example, the following two valency formulas:
Hydrogen, sodium, potassium, silver, positive one valent, calcium, barium, magnesium, zinc, positive bivalent, one or two copper, two three iron, two tetra iron, two tetra carbon, three aluminum, four silicon, three or five phosphorus, and manganese, chloride and nitrogen.
Potassium, sodium, hydrogen, silver, positive bivalent, calcium, magnesium, zinc, barium, positive bivalent, fluorochlorobromo, iodine negative bivalent, usually oxygen is negative bivalent, copper is positive 12, aluminum is positive, iron has positive 2 and positive, carbon has positive 2 and positive4, sulfur has negative 2, positive, 46.
After memorizing the valency formula, you have a certain foundation.
2. First mark the valency of some elements with only one valence, and then further mark the most commonly used valency of a certain element, such as oxygen, its compound can be negative bivalent or negative monovalent (oxygen is negative monovalent in peroxide), and finally according to the principle of positive and negative valency algebra and zero (note: to bring in the corner mark to calculate), determine the valency of unknown elements or elements with more valence.
For example: the valency of sodium bisulfite is marked: first determine that sodium and hydrogen are positive monovalent, oxygen is generally negative bivalent, and the valency of sulfur elements is more, we can calculate its valency according to the algebra of positive and negative valency algebra and zero, let the valency of sulfur be x, then there is 1+1+x+3 (-2)=0, and the solution is:
x=4, i.e., the valency of sulfur is positive tetravalent.
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Anonymous users2024-02-03When calculating the valency, we must first remember the valency of the commonly used elements, first of all, we must remember the valency of the commonly used elements, and after marking the valency, verify that the algebraic sum of the valency of all elements is equal to zero.
1. First of all, we must remember the valency of commonly used elements.
Such as: valency formulas for common elements:
Hydrogen, sodium, potassium, silver +1 valence, calcium, barium, magnesium and zinc +2 valence (explanation: such as hydrogen, sodium, potassium and silver are all +1 valence, and the same is true for others);
One or two shout copper, two three iron 246 sulfur 24 carbon (explanation: such as copper is +1 valence and +2 valence, other similarities, but some + valence and one valence are divided, such as: in sulfur dioxide sulfur is +4 valence, in hydrogen sulfide, sulfur is one 2 valence); three aluminum, four silicon, three or five phosphorus valence, as well as manganese, chlorine and nitrogen; There is also the most common form of oxygen that manifests itself as -2 valence (in the junior high school category).
2. First of all, we must remember the commonly used elemental valency.
3. The principle of writing chemical formulas with valence: positive valence first, negative valence last; Gold is not posterior, oxygen is right and not left; The valence is marked above: first slightly simplified, then crossed.
4. After marking the valency, verify that the algebraic sum of the valencies of all elements is equal to zero.
For example, in ferric chloride (Feci3) (Fe is +3 valence, and the number of atoms is 1, C is -1 valence, and the number of atoms is 3, calculate (+3x1+-1x3=0), that is, the algebraic sum of the valencies of all elements is equal to zero. ）
5. After memorizing the commonly used valences, you can calculate the valencies of other elements that you are not sure of according to the algebraic sum of the valencies of all Zheng Zhizhi elements, which is equal to zero.
potassium, sodium, hydrogen and silver are monovalent, calcium, magnesium, zinc, barium are bivalent; >>>More
The valency of nitrogen is 0
Valency is the property of an element when one atom of an element is combined with the atoms of another element. In general, the valence of valency is equal to the number of electrons gained and lost by each atom during compounding, that is, the number of electrons gained and lost when the element can reach a stable structure, which is often determined by the electronic configuration of the element, mainly the outermost electron configuration, and of course may also involve the substable structure composed of sublayers that the subouter shell can achieve. Valency indicates the number of electrons gained and lost by atoms when they are combined with each other. >>>More
Beginners can write a chemical formula by first writing the atoms or clusters of atoms that make up a compound and marking their chemical valences on the head, for example. >>>More
Memorize the periodic table! ~
Each cycle and each family have their characteristics. According to the family, their outer electrons are the same, and the way of losing or gaining electrons is also similar (forming a valence state), for example, alkali metals are +1, alkaline earths are more +2, halogens are -1 valence, oxygen groups are generally -2....It's good to remember the characteristics and the special oxygen group oxygen is multi-2 valence, but sulfur has any valence state, so you should pay more attention to sulfur and phosphorus are all polyvalent, and you should also look at superoxide ions when encountering them >>>More
Monovalent potassium hydrochloride sodium silver.
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