Mendeleev
How many elements were in the periodic table that Mendeleev produced?
63
Who was Mendeleev's student that ordered the periodic table in order of atomic number?
Henry Moseley
What element has one valence electron in the outer shell but is not a alkali metal
Hydrogen
May have irregular electron configuration
transition elements
Hydrogen is one
Noble gasses
Mendeleev noticed that the properties of elements repeated so he did what in his design of the of the periodic table?
Mendeleev started a new row each time he noticed the properties of elements repeated.
The periodic law is what?
Periodic law is when elements are arranged according to atomic number, elements with similar properties appear at regular intervals.
2
The most reactive nonmentals
Halogens
Noble gasses
Mendeleev created a table in which elements with similar ______were grouped together.
properties
triads
What elements are harder and denser than alkali metal
alkaline earth metals
Combine easily with metals to form salts
Halogens
Like hawaii and alaska in the us but on the periodic table
inner transition metals
Mendeleev proposed the original _____of the periodic table.
concept
Early philosophers proposed that matter was made of four elements, which we re what?
earth, water, fire, air
What group are the alkali metals
1
Contains 4 valence electrons
Carbon group
The last two rows of periodic table not connected
what are the inner transition metals
Mendeleev ordered in order by what measurement?
atomic mass
Who discovered the noble gasses?
William Ramsay
alkali metals
Is in the middle of the periodic table?
transition elements
One period of elements is shiny and reactive the other unstable.
Inner transition metals.