Development of the periodic table

• Who was Dmitri Mendeleev?

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

  The periodic table of elements
• What does the periodic table organize?

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

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

  By increasing atomic number
• What does the atomic number represent?

  The number of protons in an atom
• What is found within each box of the periodic table?

  The nucleus symbol for that element
• What is the elemental symbol for sodium?

  Na
• What does the atomic number indicate?

  How many protons the atoms have
• What does the mass number tell us?

  Total number of protons and neutrons
• What pattern did Mendeleev observe in the elements?

  Chemical properties repeated at regular intervals
• What are the horizontal rows in the periodic table called?

  Periods
• What do the vertical columns in the periodic table represent?

  Groups with similar chemical properties
• How many groups are there in the periodic table?

  Seven groups
• What is the exception for the far-right group in the periodic table?

  It is called group 0, not group 8
• Why do elements in the same group have similar properties?

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

  Two electrons
• What are the elements in group one called?

  Alkali metals
• What do all group one elements have in common?

  One electron in the outer shell
• How do group one elements react with water?

  They react violently
• What trend is observed in group one elements as you move down the group?

  They become more reactive
• What are group seven elements called?

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

  Seven electrons
• What trend is observed in group seven elements as you move down the group?

  They become less reactive
• What are the elements in group zero called?

  Noble gases
• What do noble gases have in their outer shells?

  Full outer shells
• How many electrons does argon have in its outer shell?

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

  Two out of two
• Why are noble gases unreactive?

  They do not need to gain or lose electrons
• What does the zigzag line in the periodic table separate?

  Metals from nonmetals
• What is the special block of elements in the middle of metals called?

  Transition metals
• What should you remember about different types of periodic tables?

  They present the same information differently
• How can you identify the atomic number in a periodic table?

  It is the smaller of the two numbers
• What will the periodic table in your exam resemble?

  Similar to the one used in the video