Chapter 1.3 Vocabulary

Chapter 1.2 Vocabulary **atomic number:** the number of protons in one atom of an element **atomic weight:** the weighted average mass of the isotopes of an element **electron:** a negatively charged subatomic particle outside the nucleus of an atom **isotope:** an atom of an element that has th...

Chapter 1.2 Vocabulary **atomic number:** the number of protons in one atom of an element **atomic weight:** the weighted average mass of the isotopes of an element **electron:** a negatively charged subatomic particle outside the nucleus of an atom **isotope:** an atom of an element that has the same atomic number but a different number of neutrons and a different mass number **mass number:** the sum of the number of protons and neutrons in an atom's nucleus **neutron:** a subatomic particle that has no charge in the nucleus of an atom **nucleus:** the center of an atom that contains protons and neutrons and is surrounded by an electron cloud **proton:** a positively charged subatomic particle in the nucleus of every atom **group**: a vertical column of elements in the periodic table **metal:** an element that is usually hard, shiny, malleable, ductile, and a good conductor of heat and electricity **nonmetal:** an element that is usually soft, not malleable or ductile, and a poor conductor of heat and electricity **period:** a horizontal row of elements in the periodic table **periodic table:** an organized arrangement of elements in order of increasing atomic number with repeating physical and chemical property pattern