Chapter 4: Periodic Table Flashcards
Ancient Greeks thought that all matter in the universe was made of only how many elements?
5
Do the symbols of each element always use just two letters?
No
Who recognized groups of three elements with similar properties?
Johann Doberiener
How did the ideas of triads influence the development of the periodic table, even though more than three elements share similar properties?
-Established element families
-Established element groups numbered 1-18
-Gave rise to the idea of octaves.
Who observed that when the elements were arranged by increasing atomic mass, every eighth element often had similar properties?
John Newlands
What was the unique feature of Mendeleev’s classification method?
The blank spaces that he left between elements.
Do the properties of elements vary in a periodic way?
Yes
Which scientist’s discoveries led to organization the periodic table using atomic numbers rather than atomic mass?
Henry Mosely
What is the modern periodic table arranged by?
Atomic number
Elements in the same ________ on the periodic table have the same number of valence electrons.
Column
How many periods does the modern periodic table have?
7
How many groups does the modern periodic table have?
18
Is a family the same as a period on a periodic table?
No
The first two elements of the periodic table, hydrogen and helium, are in the same what?
Period
How would a highly conductive, malleable, and lustrous solid most likely be classified?
Metal
What are the general properties of metals?
Dense, lusterous, highly conductive, reactive, malleable, ductile, have few valence electrons
What group is highly conductive and reactive?
Metals
What group are ductile, malleable, and lusterous?
Metals
What group includes almost 80% of the elements?
Metals
Where are metalloids found on the periodic table?
Along the stair step line
What group exists naturally as a gas, liquid, or a dull solid?
Nonmetals
Which group are semiconductors?
Metalloids
Which group possesses four to eight valence electrons?
Nonmetals
Where are nonmetals found on the periodic table?
To the right, but not touching the stair step line.
