ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Periodic Table for Chemistry

Updated on November 29, 2012

Dmitri Mendeleev (1834-1907)

Dmitri Mendeleev is widely credited with creating the first Periodic Table of Elements.
Dmitri Mendeleev is widely credited with creating the first Periodic Table of Elements. | Source

What is the Periodic Table?

The Periodic Table of Elements is a way of organising all 118 known elements, according to their physical properties and chemical behaviour. The table allows us to accurately predict the behaviour of different elements when they react together. But this raises a more basic question:

What is an element?

Put simply, an element is a 'pure' substance made of only one type of atom. Atoms themselves are made of protons, electrons and neutrons; each element has a different and fixed number of protons, neutrons and electrons. For example, Helium (He) has 2 protons, 2 electrons and 2 neutrons.

How is the Periodic Table Arranged?

As you move across the periodic table, the number of protons in the nucleus of the atom increases by one. Lithium has 3 protons, Beryllium has 4 protons, Boron has 5 protons, and so on.

There are several organisational elements to the periodic table. Most importantly are the rows and columns:

  • The rows of the table are known as periods. These go across the table (My chemistry teacher taught me to remember this by thinking that girls get cross on their periods, and periods go across the table). Moving left to right atomic radius tends to decrease, and electronegativity increases.
  • The columns of the table are known as groups. These go up and down the table (My chemistry treacher taught me to remember this by thinking that groups go up and down in the charts, and groups go up and down in the table) Every element in a group has the same number of electrons in it's outer shell - giving each group similar chemical properties. Moving down a group, atomic radius tends to increase and electronegativity decreases.

The table can also be organised as metals, metalloids and non-metals; as well as according to blocks.

What is the Periodic Table?

The Modern Periodic Table: Based on the original created by Dmitri Mendeleev. The table arranges elements by their mass.
The Modern Periodic Table: Based on the original created by Dmitri Mendeleev. The table arranges elements by their mass. | Source

Trends of the Periodic Table

The trends of the periodic table. Electron affinity is also known as electronegativity - the ability of an atom to attract electrons towards itself.
The trends of the periodic table. Electron affinity is also known as electronegativity - the ability of an atom to attract electrons towards itself. | Source

Who Invented the Periodic Table?

There were several attempts to organise the known elements before the modern Table was invented. John Newlands thought he found groups of seven elements, which he termed 'octaves'. Unfortunately, when a new element was discovered (in the 19th Century they were being discovered at a rate of about 1 per year) the new elements did not fit neatly into Newlands' pattern.

A Russian chemist, Dmitri Mendeleev, was the first person to create an organisational method for the elements that not only incorporated newly discovered elements, but actively and accurately predicted their existence and their potential properties.

Mendeleev did three things differently to his colleagues:

  1. He did not try to make a completely regular grid - some rows were longer than others.
  2. If the elements didn't fit his table, he swapped things round. If they still didn't fit, he told the experimenters they must have got the masses of the elements wrong.
  3. He left gaps for elements that had not been discovered yet.

The Elements Song!

What do the Numbers on the Periodic Table Mean?

One of the impressive things Mendeleev managed was to accurately predict the physical and chemical properties of undiscovered elements. The fact that Mendeleev could predict the existence of an element that nobody had discovered is amazing enough, but how could he also predict their properties?

It's all down to what the numbers on the Periodic Table mean.

Each symbol is flanked by two numbers:

  • The Atomic number: This shows the number of protons in the nucleus of the atom. This is also the number of electrons in the atom
  • The Mass number: this shows the numbers of protons and neutrons in the atom. This constitutes most of the mass of the atom (electrons have negligible mass)

The properties of an atom depend on it's electronegativity, ionisation energy and number of electrons in the outer valence. All of these properties are determined by the number of protons and electrons in the atom. As Mendeleev could accurately predict the number of protons and electrons in an atom, he could predict the chemical properties that would go with them. Mendeleev also knew the properties of the elements surrounding his predicted gaps - which further helped him to predict the properties of the undiscovered elements.

What do Atomic Symbols Mean

Standard notation for atomic symbols. Symbols are international, so chemists in Japan can understand chemical equations from chemists in Sweden.
Standard notation for atomic symbols. Symbols are international, so chemists in Japan can understand chemical equations from chemists in Sweden. | Source

Periodic Table Summary

Who Decides if Something is an Element?

A
IUPACC Secretariat:
Durham, NC 27709, USA

get directions

The International Union of Pure and Applied Chemistry is the body that decides what goes on the Periodic Table, and what that element is called.

Comments

    0 of 8192 characters used
    Post Comment

    • Tedyliza Ramos profile image

      Tedyliza Ramos 

      9 months ago

      RAMOS TEDYLIZA ROSE C.

      BSTM 4

      (TUTORIAL/FRIDAY)

      The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number, electron configuration, and recurring chemical properties. This ordering shows periodic trends, such as elements with similar behaviour in the same column. It also shows four rectangular blocks with some approximately similar chemical properties

    • Austinstar profile image

      Lela 

      5 years ago from Somewhere near the center of Texas

      Chemistry, the study of all that matters. A little joke.

      Easy enough to understand the way you explain it here, but my chemistry teacher was not so eloquent. Therefore, I never learned what all this meant.

      Thanks for the explanation!

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)