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Atoms
Chemistry
Term | Definition |
---|---|
Atom | The basic particle from which all elements are made |
Electron | A tiny negatively charged particle that moves around the outside of the nucleus of an atom |
Nucleus | In cells a large oval organelle that contains the cells genetic material in the form of DNA and controls many cell activities |
Proton | Small positively charged particles that are found in the nucleus of an atom |
Energy level | A region of an atom in which electrons of the same energy are likely to be found |
Neutron | A small particle in the nucleus of the atom with no electrical charge |
Atomic number | The number of protons in the nucleus of an atom |
Isotope | An atom with the same number of protons and a different number of neutrons from other atoms of the same element |
Mass number | The sum of protons and neutrons in the nucleus of an atom |
Atomic mass | The average mass of all the isotopes of an element |
Periodic table | An arrangement of the elements showing the repeating pattern of their properties |
Chemical symbol | A one- or two- letter representation of an element |
Period | a horizontal row of elements in the periodic table |
Group | Elements in the same vertical column of the periodic table also called family |