Played a lead role in developing the structure of the modern periodic table and predicted the existence of several missing elements at the time of his work
Dmitri Mendeleev
Formulated the concept of traids
Johann Dobereiner
Proposed that elemental properties varied in octaves
John Newlands
Ordered the periodic table by atomic number
Henry Moseley
Devised the commonly used elecronegativity scale
Linus Pauling
The purpose of the periodic table
Organizes the elements so their properties can be remembered
Why were several elements in odd places in Mendeleev’s Table?
The table was organized by mass
How was the problem of several elements in odd places in Mendeleev’s Table fixed?
Ordering the elements in groups
Two names for the horizontal rows in the periodic table
Periods or Series
Two names for the vertical rows in the periodic table
Groups or Families
The groups that are considered the representative groups
Group 1,2, and 13-18
Alkali Metal Family or Group 1
Alkaline-Earth Metal Family or Group 2
Transition Metals Family or Group 3-12
Inner Transition Metals
Boron Family or Group 13
Carbon Family or Group 14
Nitrogen Family or Group 15
Oxygen Family or Group 16
Halogen Family or Group 17
Noble Gas Family or Group 18
Why are sodium cations smaller than sodium atoms?
Sodium cations are sodium atoms that lost their outer shell
Why are chlorine anions larger than chlorine atoms?
Chlorine anions are chlorine atoms that gain electrons
Which of the 18 elements in the 4th period has the largest atomic radius, smallest first ionization energy, lowest electronegativity, and is found in salt replacements?
Potassium (K)
Which of the 18 elements in the 4th period has the lowest electron affinity?
Bromine (Br)
Which of the 18 elements in the 4th period has the highest electronegativity?
Bromine (Br) and Krypton (Kr)
Which of the 18 elements in the 4th period are semiconductors?
Arsenic (As) and Germanium (Ge)
Which of the 18 elements in the 4th period is one of the least reactive elements?
Krypton (Kr)
Which of the stable alkaline-earth metals (Be, Mg, Ca, Sr, and Ba) has the largest atomic radius, has the largest ionic radius, and has the smallest electronegativity?
Barium (Ba)
Which of the stable alkaline-earth metals (Be, Mg, Ca, Sr, and Ba) has the largest ionization energy?
Berylium (Be)
What is most atypical about the alkali metals compared to other metals?
They are soft and have low densities
Why were pure metals like gold, silver and copper known in Old Testament times but metals like sodium, aluminum, and potassium not discovered until relatively recently?
They do not occur naturally
Why was chlorine (Cl) isolated before fluorine (F)?
Chlorine (Cl) is less active
Metalloid
Antimony (Sb)
Transition Metals
Tungsten (W)
Noble Gas
Argon (Ar)
Transition Metals
Iron (Fe)
Halogen
Bromine (Br)
Alkali Metals
Cesium (Cs)
Lanthanide
Cerium (Ce)
Actinide
Uranium (U)
Alkaline-Earth Metals
Calcium (Ca)
Alkali Metal
Lithium (Li)
Gaseous at room temperature
Fluorine (F), Hydrogen (H), Helium (He), Oxygen (O)
Liquid at room temperature
Bromine (Br), Mercury (Hg)
Soft Metal
Caesium (Cs), Potassium (K), Sodium (Na)
Constituent of table salt
Sodium (Na)
Responsible for making water hard
Calcium (Ca) and Magnesium (Mg)
Relatively inactive solid metal
Gold (Au)
Found in glass and many minerals
Silicon (Si)
Constitute of bauxite
Aluminium (Al)
Glows in the dark
Phosphorus (P)
Called brimstone in the Bible
Sulfur (S)
Most electronegative element
Fluorine (F)
Required for proper function of the thyroid gland
Iodine (I)
Used in balloons
Helium (He)
Gas chemically similar to alkali metals
Hydrogen (H)
