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 mostly made in laboratories. The quantity of protons in an element is its atomic number. Elements arranged in horizontal rows based on atomic numbers are periods. Lanthanides are the elements in the top row of the inner - transition series sometimes called rare - earth metals. Elements arranged in vertical columns based on chemical properties 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