Atomic number
Lesson Flashcards: The Periodic Table Chemistry • 10th Grade
The number of protons in the nucleus of an atom
Ion
An atom (or molecule) that has either gained or lost one or more electrons and therefore has a net negative or positive charge, respectively
Metalloids
Elements that display the properties of both metals and nonmetals
Lustrous
The property of reflecting light evenly and efficiently without glitter or sparkle
Ductile
The property of being drawn out into thin wires
Periods
The horizontal rows in the periodic table
Halogens
The collection of elements found in group 17 of the periodic table
Alkali metals
The collection of elements found in group 1 of the periodic table
Groups
The vertical columns in the periodic table
Alkaline earth metals
The collection of elements found in group 2 of the periodic table
Noble gases
The collection of elements found in group 18 of the periodic table