Why is the periodic table called the periodic table? The concepts of families and periods in the periodic table

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, with spaces left in some periods so that elements with similar properties are grouped in the same family. Have you ever wondered why the periodic table is called the periodic table? Is there any pattern behind it? Open it and take a look!

Contents of this article

1. Why is the periodic table called the periodic table?

2. The concepts of groups and periods in the periodic table

3. How to memorize the periodic table of chemical elements in grade 9

Why is the periodic table called the periodic table?

Different outermost charge numbers determine the chemical properties of elements. As the number of protons in the nucleus increases, the number of electrons in the outermost layer will also increase periodically, thus determining the periodic recurrence of the chemical properties of the elements. The chemical properties of a column of elements in the periodic table are similar. Each row transitions from strong reducing to strong oxidizing from left to right. The last column is an inert gas that hardly undergoes chemical reactions.

The concept of groups and periods in the periodic table

The periodic table of chemical elements is a list of chemical elements in ascending order of atomic number. The list is generally rectangular, with spaces in some periods to group elements with similar properties, such as halogens, alkali metals, and rare gases (also known as inert gases or noble gases). This results in the formation of element divisions in the periodic table, which are divided into seven main groups, seven subgroups, and zero and eight groups. The periodic table is widely used in chemistry and other scientific fields as a useful framework for analyzing chemical behavior because it can accurately predict the properties of various elements and the relationships between them.

A horizontal row in which elements with the same number of electron layers are arranged from left to right in order of increasing atomic number is called a period; a vertical row in which elements with the same number of outermost electrons are arranged from top to bottom in order of increasing number of electron layers is called a group.

How to memorize the periodic table of chemical elements in grade 9

You can remember it by:

1. Break the whole into parts and disperse the memory. Start with the common element symbols, adopt the strategy of breaking the whole into parts, and consciously memorize them in different categories and from multiple angles. For example, first remember the element symbols learned in each lesson, and gradually master the element symbols that are similar to pinyin in future studies.

2. For easily confused symbols, compare and memorize them. For element symbols that consist of two letters and have the same first capital letter or second lowercase letter, you may want to list them separately and use comparison to strengthen your memory.

3. Compile poems and memorize them in rhymes. The first volume of the junior high school textbook requires you to memorize and master 27 elements, including 13 non-metallic elements and 14 metallic elements. If you compile these 27 elements into rhymed poems, memorizing them can become more interesting and vivid.