CFA 8.5C

The periodic table is organized into groups and periods of elements. The characteristics of a certain group of elements are listed above. Which of these elements is in this group?

Which two elements on the periodic table are in the same period?

Which two elements on the periodic table have similar reactivity

A student is studying the ways different elements are similar to one another. Diagrams of atoms from four different elements are shown above. Which two atoms are in the same period in the periodic table?