Video Transcript
Which arrow corresponds to group
one of the periodic table?
Each column of the periodic table
is called a group. Atoms of elements found in the same
group have the same number of outermost electrons. This highlighted group contains the
elements fluorine, chlorine, and bromine. An atom of each of these elements
has a different number of electrons and a different number of energy levels. But they each contain seven
electrons in their outermost energy level.
The groups of the periodic table
are numbered one through 18 from left to right. We may also encounter an older
numbering scheme for groups, where elements on the left and right of the periodic
table have group numbers one A through seven A and zero, while elements in the
middle of the periodic table have the numbers one B through eight B. As the groups of the periodic table
are numbered from left to right, group one corresponds to the leftmost column.
Therefore, the arrow that
corresponds to group one of the periodic table is the arrow labeled A.
