Mendeleev arranged the elements in his periodic table in order of what?
Mendeleev's decision to leave gaps in his periodic table was supported by the discovery of what?
In the modern periodic table, elements are arranged in order of what?
How many periods does the periodic table have?
An atomic mass unit is what?
the twelfth the mass of a carbon -12
An element that is shiny and conducts electric currents is likely to be a what?
Copper is an example of what?
Elements that have the same number of valence electrons are what?
in the same group
The most reactive metals are the what group?
Which group are all gases at room temp.?
Please allow access to your computer’s microphone to use Voice Recording.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Your microphone is muted
For help fixing this issue, see this FAQ.