development of the periodic table

• Who was Dmitri Mendeleev?


  A Russian chemist and inventor
• What significant contribution did Mendeleev make in the mid-nineteenth century?


  He devised the periodic table
• What does the periodic table organize?


  All of the known elements
• What did Mendeleev's periodic table predict?


  New elements that had not been discovered yet
• How are the elements arranged in the periodic table?


  In order of increasing atomic number
• What does the atomic number represent?


  The number of protons in the atoms of that element
• What three components are found within each box of the periodic table?


  Elemental symbol, atomic number, and mass number
• What is the elemental symbol for sodium?


  Na
• What does the atomic number tell us?


  How many protons the atoms of that element have
• What does the mass number indicate?


  The total number of protons and neutrons in that atom
• Why did Mendeleev form a new row in the periodic table?


  Because the elements displayed a pattern of chemical properties that repeated
• What do we call the rows in the periodic table?

  Periods
• What do the elements in each vertical column of the periodic table have in common?


  They have similar chemical properties
• What is the term used for the vertical columns in the periodic table?

  Groups
• How many groups are there in the periodic table?


  Seven, with the far-right group called group 0
• Why do elements in the same group have similar chemical properties?


  They have the same number of electrons in their outermost shell
• How many electrons do elements in group two have in their outermost shell?


  Two electrons
• What are the group one elements called?


  Alkali metals
• What is a characteristic property of group one elements?


  They all react violently with water
• How does reactivity change among group one elements?


  They become more reactive as you go down the group
• What are group seven elements called?

  Halogens
• How many electrons do group seven elements have in their outer shell?


  Seven electrons
• How does reactivity change among group seven elements?


  They become less reactive as you go down the group
• What are group zero elements known as?

  Noble gases
• What is unique about the outer shells of noble gases?


  They all have full outer shells
• How many electrons does argon have in its outer shell?


  Eight electrons
• How many electrons does helium have in its outer shell?


  Two electrons
• Why are noble gases considered unreactive?


  They don't need to gain or lose any electrons
• What does the zigzag line in the periodic table separate?


  Metals from nonmetals
• What is the characteristic of metals in the periodic table?


  There are more metals than nonmetals
• What is the special block of elements in the middle of metals called?

  Transition metals
• What should you do if you find different types of periodic tables online?


  Don't worry, they all provide the same information
• How can you identify the atomic number in a periodic table?


  It will be the smaller of the two numbers
• What will the periodic table provided in an exam be similar to?


  It will be similar to the one used throughout the video
• What should you do if you enjoyed the video?


  Give a like and subscribe