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- https://chem.libretexts.org/Courses/Modesto_Junior_College/Chemistry_143%3A_Introductory_College_Chemistry_(Brzezinski)/CHEM_143%3A_Text_(Brzezinski)/04%3A_Atoms_and_Elements/4.02%3A_The_Nuclear_Atom/4.2.01%3A_The_Properties_of_Protons%2C_Neutrons%2C_and_ElectronsElectrons are extremely small. The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an e...Electrons are extremely small. The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an electric charge of −1, which is equal but opposite to the charge of a proton, which is +1. All atoms have the same number of electrons as protons, so the positive and negative charges "cancel out", making atoms electrically neutral.
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/DMA_Chem_51/2%3A_Beginning_Chemistry_(Ball)/03%3A_Atoms_Molecules_and_Ions/3.4%3A_Masses_of_Atoms_and_MoleculesThe atomic mass unit (u) is a unit that describes the masses of individual atoms and molecules. The atomic mass is the weighted average of the masses of all isotopes of an element. The molecular mass ...The atomic mass unit (u) is a unit that describes the masses of individual atoms and molecules. The atomic mass is the weighted average of the masses of all isotopes of an element. The molecular mass is the sum of the masses of the atoms in a molecule.
- https://chem.libretexts.org/Under_Construction/Purgatory/CHEM_2100%3A_General_Chemistry_I_(Mink)/02%3A_Atoms_Molecules_and_Ions/2.04%3A_Atomic_Structure_and_SymbolismAn atom consists of a small, positively charged nucleus surrounded by electrons. The nucleus contains protons and neutrons; its diameter is about 100,000 times smaller than that of the atom. The mass ...An atom consists of a small, positively charged nucleus surrounded by electrons. The nucleus contains protons and neutrons; its diameter is about 100,000 times smaller than that of the atom. The mass of one atom is usually expressed in atomic mass units (amu), which is referred to as the atomic mass. An amu is defined as exactly 1/12 of the mass of a carbon-12 atom and is equal to 1.6605 × 10−24 g.
- https://chem.libretexts.org/Courses/CSU_San_Bernardino/CHEM_2200%3A_General_Chemistry_II_(Mink)/02%3A_Atoms_Molecules_and_Ions/2.04%3A_Atomic_Structure_and_SymbolismAn atom consists of a small, positively charged nucleus surrounded by electrons. The nucleus contains protons and neutrons; its diameter is about 100,000 times smaller than that of the atom. The mass ...An atom consists of a small, positively charged nucleus surrounded by electrons. The nucleus contains protons and neutrons; its diameter is about 100,000 times smaller than that of the atom. The mass of one atom is usually expressed in atomic mass units (amu), which is referred to as the atomic mass. An amu is defined as exactly 1/12 of the mass of a carbon-12 atom and is equal to 1.6605 × 10−24 g.
- https://chem.libretexts.org/Courses/Grand_Rapids_Community_College/CHM_120%3A_Survey_of_General_Chemistry_(Crandell)/02%3A_Measurements_and_the_Periodic_Table/2.06%3A_Atomic_Structure_and_SymbolismAn atom consists of a small, positively charged nucleus surrounded by electrons. The nucleus contains protons and neutrons; its diameter is about 100,000 times smaller than that of the atom. The mass ...An atom consists of a small, positively charged nucleus surrounded by electrons. The nucleus contains protons and neutrons; its diameter is about 100,000 times smaller than that of the atom. The mass of one atom is usually expressed in atomic mass units (amu), which is referred to as the atomic mass. An amu is defined as exactly 1/12 of the mass of a carbon-12 atom and is equal to 1.6605 × 10−24 g.
- https://chem.libretexts.org/Courses/Fullerton_College/Beginning_Chemistry_(Chan)/07%3A_Stoichiometry_and_the_Mole/7.03%3A_The_MoleThe mole is a key unit in chemistry. The molar mass of a substance, in grams, is numerically equal to one atom's or molecule's mass in atomic mass units.
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Chem_51/1.8%3A_Stoichiometry_and_the_Mole/8.01%3A__Masses_of_Atoms_and_MoleculesThe atomic mass unit (u) is a unit that describes the masses of individual atoms and molecules. The atomic mass is the weighted average of the masses of all isotopes of an element. The molecular mass ...The atomic mass unit (u) is a unit that describes the masses of individual atoms and molecules. The atomic mass is the weighted average of the masses of all isotopes of an element. The molecular mass is the sum of the masses of the atoms in a molecule.
- https://chem.libretexts.org/Courses/Indiana_Tech/EWC%3A_CHEM_1000_-_Introductory_Chemistry_(Budhi)/04%3A_Atoms_and_Elements/4.4%3A_The_Properties_of_Protons%2C_Neutrons%2C_and_ElectronsElectrons are extremely small. The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an e...Electrons are extremely small. The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an electric charge of −1, which is equal but opposite to the charge of a proton, which is +1. All atoms have the same number of electrons as protons, so the positive and negative charges "cancel out", making atoms electrically neutral.
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/Hybrid_Chem_51_v1/04%3A_Atoms_Molecules_and_Ions/3.5_Masses_of_Atoms_and_MoleculesThe atomic mass unit (u) is a unit that describes the masses of individual atoms and molecules. The atomic mass is the weighted average of the masses of all isotopes of an element. The molecular mass ...The atomic mass unit (u) is a unit that describes the masses of individual atoms and molecules. The atomic mass is the weighted average of the masses of all isotopes of an element. The molecular mass is the sum of the masses of the atoms in a molecule.
- https://chem.libretexts.org/Bookshelves/General_Chemistry/Chemistry_2e_(OpenStax)/02%3A_Atoms_Molecules_and_Ions/2.03%3A_Atomic_Structure_and_SymbolismAn atom consists of a small, positively charged nucleus surrounded by electrons. The nucleus contains protons and neutrons; its diameter is about 100,000 times smaller than that of the atom. The mass ...An atom consists of a small, positively charged nucleus surrounded by electrons. The nucleus contains protons and neutrons; its diameter is about 100,000 times smaller than that of the atom. The mass of one atom is usually expressed in atomic mass units (amu), which is referred to as the atomic mass. An amu is defined as exactly 1/12 of the mass of a carbon-12 atom and is equal to 1.6605 × 10−24 g.
- https://chem.libretexts.org/Courses/University_of_Missouri/MU%3A__1330H_(Keller)/02._Atoms_Molecules_and_Ions/2.3%3A_The_Modern_View_of_Atomic_StructureEach atom of an element contains the same number of protons, which is the atomic number (Z). Neutral atoms have the same number of electrons and protons. Atoms of an element that contain different num...Each atom of an element contains the same number of protons, which is the atomic number (Z). Neutral atoms have the same number of electrons and protons. Atoms of an element that contain different numbers of neutrons are called isotopes. Each isotope of a given element has the same atomic number but a different mass number (A), which is the sum of the numbers of protons and neutrons. The relative masses of atoms are reported using the atomic mass unit (amu).
