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Chapter 17
Atoms
Term | Definition |
---|---|
Atom | The smallest piece of matter that still retains the property of the element. |
Atomic Number | The number of protons in an atom is equal to a number. |
Average Atomic Mass | The weighted average mass of the mixture of an element's isotopes. |
Electron | Particles with an electrical charge of 1+. |
Electron Cloud | The area around the nucleus of an atom where its electrons are most likely found. |
Electron Dot Diagram | Uses the symbol of the element and dots to represent the electrons in the outer energy level |
Groups | The vertical columns in the periodic table; also called families. |
Isotopes | Atoms of the same element that have different numbers of neutrons. |
mass number | Sum of the number of protons and neutrons in an atom's nucleus. |
neutron | Neutral particle, composed of quarks, inside the nucleus of an atom. |
nucleus | Positively charged center of an atom that contains protons and neutrons and is surrounded by a cloud of electrons. |
period | Horizontal row in the periodic table. The amount of time it takes one wavelength to pass a fixed point; is expressed in seconds. |
periodic table | Organized list of all known elements that are arranged by increasing atomic number and by changes in chemical and physical properties. |
proton | Particle, composed of quarks, inside the nucleus of an atom that has a charge of 1+. |
quark | Particles of matter that make up protons and neutrons. |