periodic table Flashcards
how did mendeleev order his elements
normally by atomic mass but some elements were swapped around
how does the modern periodic table order elements
by atomic number
did mendeleev leave gaps in his periodic table
yes
why did mendeleev leave gaps in his periodic table
for undiscovered elements
how did mendeleev group elements in his periodic table
by chemical properties
how does the modern periodic table group elements?
grouped by the number of electrons in the outer shells
what were some problems with Mendeleev’s is periodic table
incomplete
no explanation for why some elements had to be swapped to fit in with appropriate groups
What are group 0 elements?
Noble gases
what are group 7 elements?
Halogens
how is the reactivity shown in group 7
reactivity decreases when you go down group 7
