if you want to remove an article from website contact us from top.

    how many periods and groups are present in the periodic table


    Guys, does anyone know the answer?

    get how many periods and groups are present in the periodic table from screen.

    How to Read the Periodic Table

    You will about the periodic table, how to read it and understand the groups on the periodic table, plus the periods & families of elements.


    How to Read the Periodic Table

    February 3, 2023 Posted by Rylie Maziek

    22 MAR

    Core Concepts:

    In this tutorial, you will learn how to read the periodic table. We will take a close look at the groups of the periodic table. In addition, you will learn about the different properties of the periodic table groups, periods, and families. If you enjoy this article, be sure to check out our others!

    Related Articles:

    Periodic Trends Made Easy


    How to Write Electron Shell Configurations

    Atomic Radius Trend

    Ionization Energy Trend

    Periodic Table with Element Names


    Elements: A pure substance composed of a single atom with a unique atomic number.

    Groups: The vertical column of the periodic table that signifies the number of valence electrons in an element.

    Periods: The horizontal rows in the periodic table that signify the number of electron shells in an element.

    Families: Elements that have the same number of valence electrons and therefore similar properties.

    View trends, families & groups interactively!

    We think our periodic table is one of the best in the world! Visit our new interactive periodic table. You can view all sorts of trends, properties, magnetism, electrons, and even articles on all the elements!

    The Periodic Table and the Periodic Trends

    The periodic table is organized into groups (vertical columns), periods (horizontal rows), and families (groups of elements that are similar). Elements in the same group have the same number of valence electrons. Meanwhile, elements in the same period have the same number of occupied electron shells. In 1869 Russian chemist Dmitri Mendeleev noticed there existed an innate pattern of organization for the chemical elements. From this deduction, he formed the periodic table. It is important to note how the location of elements on this table tells us about their properties. A quick way to understand an element’s chemical and physical properties is to know the periodic trends. These trends tell you where the highest and lowest types of properties are concentrated on the periodic table. For a more in-depth explanation of periodic trends, click here.

    Group vs Period

    Groups are the columns of the periodic table, and periods are the rows. There are 18 groups, and there are 7 periods plus the lanthanides and actinides.

    Periods on the Periodic Table

    So what is a period on the periodic table? Periods are the horizontal rows of the periodic table. There are seven periods total and each element in a period has the same number of atomic orbitals. The top period, which contains hydrogen and helium, has only two orbitals. As you go down the rows, the number of orbitals increases. Below is a table to help visuals the periodic number and the corresponding orbitals.

    Period Number Number of Orbitals Number of Elements1 1 22 2 83 3 84 4 185 5 186 6 327 7 32

    Groups of the Periodic Table

    As previously mentioned, the vertical columns on the periodic table are called “groups”. There is eighteen groups on the periodic table in total, and each periodic table group contains elements with the same number of valence electrons.

    The number of valence electrons present dictates the properties of an element. The reason for this is that the valence electrons, which are the electrons in the outermost shell, are the ones taking part in chemical reactions. These electrons are either donating, accepting, or sharing. Moreover, the more filled the valence shell is, the more stable the element.

    How many groups are in the periodic table?

    There are 18 groups in the periodic table, one per each column of the periodic table. The first column on the left is group 1, and the last column on the right is group 18.

    Groups and Valence Electrons

    The first group is the least stable as it only has one valence electron. Meanwhile, group eighteen is the most stable as these elements have a full valence shell (eight valence electrons). Below is a table relating the group numbers to the number of valence electrons.

    Group Number Number of Valence Electrons

    1 1

    2 23-12 213 314 415 516 617 718 8

    Families of the Periodic Table

    On the periodic table, there are families which are groups of elements with similar properties. These families are alkali metals, alkaline earth metals, transition metals, post-transition metals, metalloids, halogens, noble metals, and noble gases. Many of these families belong to a single group on the periodic table. However, not all of the families overlap with periodic table groups. For example, the transition metals contain all elements from group three to group twelve. Below is a periodic table where displaying the location of each family.

    स्रोत : chemistrytalk.org

    How many groups and periods are there in the modern periodic table? How do the atomic size and metallic character of elements vary as we move : i down a group and ii from left to right in a period.

    How many groups and periods are there in the modern periodic table? How do the atomic size and metallic character of elements vary as we move : i down a group and ii from left to right in a period.

    Byju's Answer Standard VII Chemistry

    Modern Periodic Table

    How many grou... Question

    How many groups and periods are there in the modern periodic table? How do the atomic size and metallic character of elements vary as we move : (i) down a group and (ii) from left to right in a period.

    Open in App Solution

    Modern periodic table:

    The modern or long form of the periodic table is based on the modern periodic law which states that; the physical and chemical properties of the elements are the periodic functions of their atomic numbers.

    The modern periodic table is the present form of the periodic table in which the arrangement of elements is in the increasing order of their atomic numbers.

    There are 18 vertical columns or groups and 7 horizontal rows or periods in the modern periodic table.

    The modern periodic table showing the 18 groups and 7 periods is given as;

    Variation of the atomic size of elements:

    The atomic radius of an element is known as a measure of the size of its atoms, which represents the mean distance from the nucleus to the outermost boundary of the surrounding cloud of electrons.

    Atomic radii vary in a predictable manner across the periodic table.

    Down a group: The atomic size and the metallic character of the elements increases accordingly.From left to right in a period: The atomic size and the metallic character of elements decrease accordingly.Variation of metallic character trend:

    Metals are substances that have a tendency to lose electrons.

    Down a group: The metallic character increases on going down to the group due to the lesser nucleus force, the electrons become easier to lose as the atomic radius increases.From left to right in a period: The metallic character decreases from left to right as the tendency of atoms for more readily accepting electrons increases by going from left to right on the periodic table.

    Hence, there are 18 groups and 7 periods in the modern periodic table. And the atomic size and metallic character of elements increase down a group and decrease from left to right in a period.

    Suggest Corrections 5



    (a) How does the size of atoms (atomic size) generally vary in going from left to right in a period of the periodic table? Why does it vary this way?

    (b) What happens to the metallic character of the elements as we move from left to right in a period of the periodic table?


    Fill in the blanks in the following statements :

    (a) The horizontal rows in a periodic table are called .............

    (b) In going across a period (right to left) in the periodic table, the atomic size of the atom .............

    (c) On moving from right to left in the second period, the number of valence electrons ..............

    (d) When we down in a group in the periodic table, the metallic character of elements ..............

    (e) The tendency to gain an electron ................ on moving down in a group of the periodic table.

    Q. (a) Which two criteria did Mendeleev use to classify the elements in his periodic table?

    (b) State Mendeleev's periodic law.

    (c) Why could no fixed position be given to hydrogen in Mendeleev's periodic table?

    (d) How and why does the atomic size vary as you go:

    (i) from left to right along a period?

    (ii) down a group?

    Q. In the modern periodic table, how does the atomic size of the elements vary along the period and down the group? Explain.Q. How do metallic character and valency of elements change in a period moving left to right in modern periodic table?



    Modern Periodic Table

    Standard VII Chemistry

    स्रोत : byjus.com

    6.4: Modern Periodic Table


    Downloads expand_more

    Download Page (PDF)

    Download Full Book (PDF)

    Resources expand_more

    Periodic Table Physics Constants

    Scientific Calculator

    Reference expand_more

    Reference & Cite Tools expand_more Help expand_more Get Help Feedback Readability

    6.4: Modern Periodic Table- Periods and Groups

    Last updated Sep 20, 2022 6.3: Periodic Law 6.5: Metals

    Figure 6.4.1 6.4.1

    (Copyright; author via source)

    How has the English dictionary evolved over time?

    Language changes with time.  New words enter the language and old words often disappear from lack of use.  Dictionaries are published so that people can keep up with changes in language and know how to use words properly.  These publications may be in print, as is the law dictionary below, or they may be electronic.  Dictionaries can be found on the internet and apps are available for smartphones.  Dictionaries are invaluable for good, reliable communication.

    The Modern Periodic Table

    The periodic table has undergone extensive changes in the time since it was originally developed by Mendeleev and Moseley. Many new elements have been discovered, while others have been artificially synthesized. Each fits properly into a group of elements with similar properties. The periodic table is an arrangement of the elements in order of their atomic numbers, so that elements with similar properties appear in the same vertical column or group.

    The figure below shows the most commonly used form of the periodic table. Each square shows the chemical symbol of the element along with its name. Notice that several of the symbols seem to be unrelated to the name of the element:

    Fe Fe for iron, Pb Pb

    for lead, etc. Most of these are the elements that have been known since ancient times and have symbols based on their Latin names. The atomic number of each element is written above the symbol.

    Figure 6.4.2 6.4.2

    (Credit: User:Cepheus/Wikimedia Commons; Source: http://commons.wikimedia.org/wiki/File:Periodic_table.svg(opens in new window); License: Public Domain)

    A period is a horizontal row of the periodic table. There are seven periods in the periodic table, with each one beginning at the far left. A new period begins when a new principal energy level begins filling with electrons. Period 1 has only two elements (hydrogen and helium), while periods 2 and 3 have 8 elements. Periods 4 and 5 have 18 elements. Periods 6 and 7 have 32 elements, because the two bottom rows that are separate from the rest of the table belong to those periods. These two rows are pulled out in order to make the table itself fit more easily onto a single page.

    A group is a vertical column of the periodic table, based on the organization of the outer shell electrons. There are a total of 18 groups. There are two different numbering systems that are commonly used to designate groups, and you should be familiar with both. The traditional system used in the United States involves the use of the letters A and B. The first two groups are 1A and 2A, while the last six groups are 3A through 8A. The middle groups use B in their titles. Unfortunately, there was a slightly different system in place in Europe. To eliminate confusion, the International Union of Pure and Applied Chemistry (IUPAC) decided that the official system for numbering groups would be a simple 1 through 18 from left to right. Many periodic tables show both systems simultaneously.

    Most recent depictions of the periodic table show an incomplete seventh period. In fact, many of those seventh period elements were not known before the early twentieth century. Many elements have been synthesized by bombarding known elements with sub-atomic particles such as neutrons or alpha particles. Uranium has been used in this manner to produce elements 93-100. Larger elements (atomic numbers 101 and above) are formed by fusing nuclei of smaller elements together.

    These synthetic elements tend to be very unstable, often existing for less than a second, so little is known about them. Elements up to atomic number 112 are known (not in any detail, however), and some evidence for elements 113 and above had been put forth, with elements 114 and 116 being added to the table in 2011. In December 2015, the ​​​​​​​IUPAC verified the existence of four new elements 113, 115, 117, and 118 and approved their addition to the periodic table.

    The following are the new element names and their origins:

    Element 113 was named Nihonium, symbol Nh, proposed by Japanese researchers after the Japanese word Nihon, which means Japan.

    A team of scientists from Russia and the United States named element 115, Moscovium, symbol Mc, after Moscow and element 117, Tennessine, symbol Ts, after Tennessee.

    स्रोत : chem.libretexts.org

    Do you want to see answer or more ?
    Mohammed 5 day ago

    Guys, does anyone know the answer?

    Click For Answer