Question

1. match the terms with the descriptions. actinides the elements at the bottom of the inner transition series that are mostly made in laboratories the quantity of protons found in an element elements arranged in horizontal rows based on their atomic numbers lanthanides the elements in the top row of the inner transition series that are sometimes called rare earth metals elements arranged in vertical columns based on their chemical properties

Explanation:

Actinides are the elements at the bottom of the inner - transition series and many are synthetic. Lanthanides are in the top row of the inner - transition series and often called rare - earth metals. The quantity of protons is the atomic number. Elements in horizontal rows are periods. Elements in vertical columns are groups.

Answer:

actinides - the elements at the bottom of the inner transition series that are mostly made in laboratories
atomic number - the quantity of protons found in an element
periods - elements arranged in horizontal rows based on their atomic numbers
lanthanides - the elements in the top row of the inner transition series that are sometimes called rare earth metals
groups - elements arranged in vertical columns based on their chemical properties