In the same column.
By looking down its column called a group
Lanthanides have properties similar to Cerium
Buttholes
Elements present within a same group normally have similar properties
is it at every tenth element
You would see which group the element was in and then replace it with another element from the same group, as all elements in a group have similar properties. For example you could replace Sodium with Potassium as they are both in Group 1.
lanthanum and other lanthanides
To find an element that is similar to another element, look in the periodic table and find an element in the same column (group/family) as the element of interest. Usually, elements within the same group/family have very similar properties.
Fluorine, at the top of the periodic table column that includes bromine.
In the columns of the periodic table, chemical properties are similar.
Groups on the periodic table with similar properties are called families.
The element in a given vertical column (or groups) have the same number of valence electrons and hence have similar properties.