Final answer:
True. Elements in a given period of Mendeleev's table have similar properties.
Step-by-step explanation:
True. Elements in a given period of Mendeleev's table have similar properties.
Mendeleev arranged the periodic table so that elements with the most similar properties were placed in the same group, which is a vertical column of the periodic table. Each row in the periodic table is referred to as a period. Elements within the same period have similar chemical properties.
For example, Group 1A, also known as the alkali metals, consists of elements with one valence electron. These elements, such as lithium, sodium, and potassium, are all very reactive and form compounds in the same ratios with similar properties with other elements in the same group.