Original definition

The ancient Greeks believed that everything in the universe was composed of water, fire, earth and air, which was called the "four elements theory". Two light elements, fire and air, will float, two heavy elements, soil and water, will sink, and four elements will form various objects in a certain proportion. China had a similar view in ancient times. Our ancestors believed that everything in the universe was made up of gold, wood, water, fire and earth.

Chemistry:

Elements refer to more than 100 kinds of basic metallic and nonmetallic substances in nature. They are only composed of several atoms with the same characteristics. Each nucleus of an atom has the same number of protons, which cannot be made simpler by general chemical methods. All substances are composed alone or in combination. It is the abbreviation of chemical element.

Precise definition of elements: a general term for a class of atoms with the same nuclear charge (or the same proton).

The difference between atoms and ions: atoms do not conduct electricity, while ions conduct electricity.

Atoms or ions with the same number of protons but different numbers of neutrons belong to the same element. Atoms or ions with the same number of protons but different numbers of neutrons are called isotopes.

Definition:

Is the floorboard of the same kind of atoms with the same number of protons (nuclear charge).

Chinese naming

Elements are represented by free radicals at room temperature (298K):

Cheng is a solid metal. Example: copper, rhodium

"Stone" is nonmetal. For example, silicon, carbon

"Qi" is Qi. Such as oxygen, fluorine

Tanya and water are liquids. For example, mercury and bromine

In addition to the common elements (gold, silver, copper, iron, platinum, tin, sulfur, carbon, boron, mercury, lead) found in ancient China, the names of elements were created in the19th and 20th centuries, and they are composed of three radicals and parts expressing pronunciation. The pronunciation part is almost entirely based on the first syllable of modern or medieval chemists or place names in Europe and North America (see # Owen's name), for example:

Erbium = Erbium+Erbium→

Nd (neodymium) = Cheng+Female → Nd

Eu (europium) = cheng =+you → europium.

Ka (potassium) = cheng+a → K.

Sodium = sodium+sodium →

Sb (antimony) = Cheng+Di → Sb (using part of the first syllable)

I (iodine) = stone+Canon → iodine (with the last syllable)

Ar (argon) = gas+sub → argon (using part of the first syllable)

Description features of Chinese names of several elements:

Bromine: It smells bad.

Chlorine: color green

Hydrogen: light weight

Nitrogen: "Light" means diluting air.

Phosphorus: phosphorescence or phosphorus fire.

Oxygen: "Nourishing" means supporting life.

Owen naming

Because the languages in Europe are closely related, except those known from ancient times, the names of the elements used are very similar, because the scientific names are all derived from the new Latin. Most elements end with "-ium", and some Roman languages end with "-io". For example, the common Owen is:

New Latin, English, German, Dutch, Danish, Swedish, Norwegian, Czech: Promethium (mostly capitalized)

French: prométhium

Spanish, Italian: prometio

Portuguese: Prometheo

Polish: promet

Catalan: prometi

Estonian: promeetium

Unlike Chinese element names, Owen's element names mostly describe characteristics, others:

About 20 from place names (all in Europe and America):

Germanium: Germany.

Yttrium (Yttrium), Terbium (Terbium) and Ytterbium (Ytterbium): All three are small towns in Iterbi, Sweden.

About 10 comes from the name of a person or a god, for example:

Curie (curium): Madame Curie.

Prometheus: The god who was punished for stealing fire in ancient Greek mythology.

Math:

Set is one of the basic concepts in mathematics. The totality of things with certain attributes is called "set", and elements are everything that constitutes a set. The branch of mathematics that studies the operations and properties of sets is called set theory or set theory.

The definition of set is very broad, not limited to mathematics, but also widely used in production and life, and all things with specific attributes that make up a specific set can be called elements, so the definition of elements is also very broad.