Chemistry S2 Vocabulary Review 2024 (M5-10, M23)

the periodic repetition of chemical and physical properties of elements when arranged by increasing atomic number

the number of protons in an atom

vertical columns of elements arranged in order of increasing atomic number on the periodic table

horizontal rows of elements arranged in order of increasing atomic number on the periodic table

elements in groups 1, 2, and 13–18

elements in groups 3–12

one of the three main classifications of the periodic table

group 1 elements, except hydrogen

group 2 elements

elements in groups 3–12, except lanthanide and actinide elements