Exactly why the relative atomic mass of Al can be counted as 18

2al+6hcl=3h2↑+2alcl3 。Al can replace 3 hydrogen molecules with a relative atomic mass of 27,54 parts of aluminum, which is about 18 parts of mass of aluminum for two parts of hydrogen, which is said for convenience in the calculation. Similarly.

Mg+2HCl=H2 +mgCl2, the relative molecular mass of MG is 24, which is 24 parts of the mass of MG for two parts of the mass of hydrogen.

Because al is positive 3 valence and the atomic weight is 27, when it is proportionally calculated as 2 valence, it becomes 18.

For example, when iron, zinc, magnesium, aluminum and other substances react with strong acids, in order to find out who releases more hydrogen per unit mass. When the amount of hydrogen they produce is the same, it can be recorded as 1mol, and the mass of aluminum consumed is 18g

For example: 2al+6hcl=3h2 +2alcl3 so 54gal can produce 6gh2.

Then write another displacement reaction, e.g. mg+2HCl=H2+mgCl2 for comparison.

The equation for the reaction of Al with hydrochloric acid is also written in this form, that is:

2 3al+2hcl=h2 +2 3alcl32 3alal is 18

When iron, zinc, magnesium, aluminum and other substances react with strong acids, in order to find out who puts more hydrogen per unit mass. When the amount of hydrogen they produce is the same, it can be recorded as 1mol, and the mass of aluminum consumed is 18g

How can the relative atomic mass of Al be counted as 18?

I can't do it.

Aluminumal】The relative atomic mass is rounded to 27. The relative atomic mass of magnesium [mg] is rounded to 24.

Atomic weight is a concept proposed by a British scientist who believes that atoms of the same element have the same mass, different elements have different atomic masses, and uses the mass of hydrogen atoms as a reference for relative atomic mass.

Later, the mass of the oxygen atom and the mass of the carbon atom were gradually used as the benchmark for the relative atomic mass, and the definition of atomic weight was finally proposed by the International Committee on Relative Atomic Mass. The mass of the carbon-12 atom selected in the world is, then, the relative atomic mass is the ratio of the atomic mass of an element to the atomic mass of carbon-12.

The relative atomic mass of mg is 24, and the relative atomic mass of Al is 27

Relative atomic masses common in junior and senior high schools:

Hydrogen: 1, Helium: 4, Carbon: 12, Nitrogen: 14, Oxygen: 16, Fluorine: 19, Neon: 20, Sodium: 23, Magnesium: 24;

Aluminum: 27, Silicon: 28, Phosphorus: 31, Sulfur: 32, Chlorine: Potassium: 39, Calcium: 40, Manganese: 55; Iron: 56;

Copper: Zinc: 65, Silver: 108, Barium: 137, Platinum: 195, Gold: 197, Mercury: 201, Iodine: 127.

The chemical symbol for aluminum is Al, and the relative atomic mass refers to the mass of the atoms in an element relative to the mass of the carbon-12 isotope. The relative atomic mass of aluminium is approximate, which is an approximation.

The relative atomic mass is determined by the periodic table, whereas aluminum is in group 13 in the periodic table with atomic number 13. For an element, the atomic number is the number of protons in the nucleus of the element, so the nucleus of aluminum contains 13 protons.

According to the composition of the element, the atom of aluminum also contains 13 electrons because the number of protons and electrons is equal in neutral atoms. In addition to protons and electrons, atoms also contain neutrons. The relative atomic mass of aluminium is about, which is determined by the sum of the masses of protons and neutrons in the nucleus of aluminum.

Knowing the relative atomic mass of aluminum is important for doing chemical calculations and equilibrium of reaction equations. It helps scientists determine the amount of substances involved in a chemical reaction and derive molar ratios, the amount of reaction products, and other relevant chemical calculations.

Aluminum is a common metal element with good electrical and thermal conductivity, so it has a wide range of applications in fields such as industry, construction, and electronics. The relative atomic mass of aluminum is an important parameter that is indispensable for the chemical calculation and study of aluminum.

Relative atomic Mass of Al:.

Aluminum is a metallic element with the element symbol Al and atomic number 13. Its elemental substance is a silvery-white light metal. Malleable. Products are often made in sticks, sheets, foils, powders, bands, and filaments.

In humid air, it can form an oxide film to prevent metal corrosion. When heated in the air, the aluminium powder burns violently and emits a dazzling white flame. Soluble in dilute sulfuric acid, nitric acid, hydrochloric acid, sodium hydroxide and potassium hydroxide solutions, insoluble in water.

Primary Uses: The use of a substance depends largely on the nature of the substance. Because of its many excellent properties, aluminum has a wide range of applications.

Aluminium and aluminium alloys are one of the most versatile and economical materials available today. Since 1956, the world's aluminum production has surpassed copper production and has been the largest non-ferrous metal. Aluminum is currently the second most widely used metal for human applications after steel in terms of production and usage (by tonnes).

Moreover, the resources of aluminum are very abundant, according to preliminary calculations, the mineral reserves of aluminum account for more than 8% of the earth's crustal constituent materials.

The relative atomic mass of Al is a silvery-white light metal, which is malleable and malleable. In humid air, it can form an oxide film to prevent metal corrosion. Aluminum powder and foil burn violently when heated in the air and emit a dazzling white flame.

Atomic mass is divided into absolute atomic mass and relative atomic mass. Absolute mass refers to the actual mass of 1 atom and can also be called the absolute mass of an atom. The relative atomic mass is the relative mass of the atom, that is, taking one-twelfth of the mass of a carbon atom as the standard, and comparing the actual mass of other atoms with it, the resulting value is the relative atomic mass of the atom.

The relative atomic mass is equal to the sum of the number of protons and the number of neutrons.

Since the mass of the electron is about one thousandth of the mass of the proton neutron, the mass of the 3 electrons lost by Al3+ is negligible.

So the relative atomic mass is 27

Don't guess and know how to ask.

If it is a bunch of the same atoms or a bunch of the same atoms (e.g., oxygen and ozone mixture): the number of atoms = total mass relative atomic mass (oxygen and ozone mixture: number of atoms = total mass of the mixture and the relative atomic mass of oxygen).

If it's a compound or a mixture of different atoms, you have to use the proportions.

If you say 'elemental mass', if you mean 'the mass of an element', then the formula is correct, otherwise it's not right.

The mass of an element can be understood as the total mass of the element, i.e., the total mass. ,5,n=m/m

Yes (unit mol).,3,Not necessarily,The relative atomic mass is calculated according to the proportion of the elements in nature,And if all of them are its other isotopes,,It cannot be calculated by this,But generally speaking,It is still calculated using this,2,Wrong。

Number of atoms = elemental mass Atomic true mass = na*elemental mass Relative atomic mass, 2, combined with the above 3 people, all have merits, 1, self-fighting is not right, relative atomic mass is relative mass, not absolute mass. Refers to the ratio of the mass of the atom to one-twelfth of the mass of carbon-12. Whereas, elemental mass, which refers to the actual mass of an atom. ,0,

Summary. Because the relative atomic mass of Na is 23

So the relative molecular mass of NaCl is.

The relative atomic mass of N Cl.

Hello, it is a pleasure to answer your questions, and the specific answers are as follows:

The relative atomic mass of N Cl (23+

Because the relative atomic mass of NaCl is 23Cl and the relative atomic mass is So, the relative molecular mass of NaCl is.

I hope it can help you, if it helps you, please give a like, thank you. (・