According to the periodic table 1 number 20 element 30

1 H Relative mass of hydrogen: 2 H Helium 3 Li Lithium 4 Be, Beryllium 5 B, Boron 6 C, Carbon 7 N, Nitrogen 8 O, 9 F Fluorine 10 Ne, Neon 11 Na, Sodium 12 mg, Mg, 13 Al, Aluminum, 14 Si, Silicon.

15 pP, 16 s, sulfur, 17 cl, chlorine, 18 ar, argon, 19 k, potassium, 20 ca, calcium.

H, hydrogen, he, helium, li, lithium, beryllium, b, boron, c, carbon, n, nitrogen, o-oxy, f, fluorine, neon, na, sodium, mg, magnesium, al, aluminum, si, silicon, p, phosphorus, s, sulfur, cl, chlorine, argon, argon, potassium, ca, calcium.

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Hydrogen, helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, neon, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, argon, potassium, calcium.

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1. Element symbols and names of elements 1-20.

Elements 1-10: H hydrogen, HE helium, LI lithium, BE beryllium, B boron, C carbon, N nitrogen, O oxygen, F fluorine, Nene.

Elements 11-20: Na sodium, mg magnesium, Al aluminum, Si silicon, P phosphorus, S sulfur, Cl chlorine, Ar argon, K potassium, Ca calcium.

2. Schematic diagram of the atomic structure of elements 1-20.

Elements 1 to 20 are as follows:

H, hydrogen, he, helium, li, lithium, beryllium, b, boron, c, carbon, n, nitrogen, o-oxy, f, fluorine, neon, na, sodium, mg, magnesium, al, aluminum, si, silicon, p, phosphorus, s, sulfur, cl, chlorine, argon, argon, potassium, ca, calcium.

Symbols for elements are unique symbols used to mark an element, and can also represent an atom of such an element, and most solid elements are also commonly represented by element symbols. Element symbols are usually represented by the first letter (uppercase) of the Latin name of an element, such as carbon-c. If the first letter of several element names is the same, add another letter (must be lowercase) in the element name after the first letter (it must be uppercase) to distinguish it, such as chlorine-cl.

The modern periodic table was created by Dmitry Mendeleev in 1869 to show the periodicity of the properties of the elements known at the time. Since then, with the discovery of new elements and the development of theoretical models, the appearance of the periodic table has changed and expanded. By way of this list, Mendeleev also ** the properties of some elements unknown at the time to fill in the blanks in the periodic table.

The subsequent discovery of new elements did indeed have similar properties, which confirmed his **.

By definition, each chemical element has its own unique atomic order, which is equal to the number of protons in its nucleus, and most elements have different numbers of neutrons in each atom, which is called an isotope.

Elements 1-20 of the periodic table of chemical elements are as follows:

Hydrogen, helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, neon.

Sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chloride, argon, potassium, calcium.

The first 20 symbols of the periodic table: H hydrogen, HE helium, LI lithium, BE beryllium, B boron, C carbon, N nitrogen, O oxygen, F fluorine, NE neon, Na sodium, MG magnesium, Al aluminum, Si silicon, P phosphorus, S sulfur, Cl chlorine, AR argon, K potassium, CA calcium.

The periodic table of chemical elements is a list of chemical elements sorted from smallest to largest according to their atomic number. The list is generally rectangular in shape, with spaces in the period of some elements, so that elements with similar characteristics are grouped into the same family, such as alkali metal elements, alkaline earth metals, halogen elements, rare gases, etc. This results in the periodic table forming an elemental partition with seven primary families, seven secondary groups, and zero families.

Because of its ability to accurately ** the properties of various elements and the relationships between them, the periodic table is widely used in chemistry and other scientific fields as a useful framework for analyzing chemical behavior.

beforeElement 20The names and symbols are: Hydrogen H, Helium He, Lithium Li, Beryllium BE, Boron B, Carbon C, Nitrogen N, Oxygen O, Fluorine F, Neon Ne, Sodium Na, Magnesium Mg, Aluminum Al, Silicon Si, Phosphorus P, Sulfur S, Chlorine Cl, Argon Argon, Potassium K, Calcium Ca.

The usual elemental form of hydrogen is hydrogen, which is colorless, tasteless and odorless, and is a highly flammable gas composed of diatomic molecules, and hydrogen is the lightest gas. Hydrogen is used in medicine to ** diseases.

Isotope. Subsequently, the British physicist Aston proved most of the chemical elements in early 1921.

All have different isotopes. The atomic weight of an element.

It is the average value of the isotope mass based on the mass fraction of the isotope present in nature. During the same period, in 1913, the British biographer Mosselle systematically studied the X-rays obtained from cathodes made of various elements.

The wavelength of the element indicates that the characteristic of the element is the number of the trapped charge of the nucleus of the atom of the element, that is, the atomic number that is determined later.