A period
The periodic table is only for elements while Ammonium is a compound radical or ion NH4+ it is combination of two elements nitrogen and hydrogen these two are in periodic table.
All of the others in the same row of the Periodic Table as sodium.
Because they have the same valence number (+2)
Elements in the same period (row) have the same number of electron shells or energy levels
The lanthanide elements are in a row at the bottom of the main part of most tables, this entire row being an extension of column 3 of the sixth period.
An elements period is its row in the periodic table.
An elements period is its row in the Periodic Table.
An elements period is its row in the Periodic Table.
Horizontal rows are called periods. There are 7 periods in periodic table.
A period is a row of elements on the periodic table.
Elements in the first row of the rare earth elements of the Periodic Table are called LANTHANIDES.
A horizontal row on the periodic table of elements is called a period.
A row.
A period is a row in the periodic table of elements.
A row on the periodic table is called a period.
litium, and elements in the 2nd period (row) are pretty common
a family is a column of elements a period is a row of elements