Atom Anatomy
Negatively charged particles
What are electrons?
a region of space around the nucleus where electrons are most likely to be found
What are orbitals?
an arrangement of elements in columns with properties that repeat from row to row
What is the periodic table?
This person developed the first atomic theory
Who is John Dalton?
Have 8 valence electrons; odorless, colorless, rare, and unreactive with other elements
What are noble gases?
the center mass of the atom
What is the nucleus?
The way electrons are arranged in the orbitals in each energy level
What is electron configuration?
Groups in the periodic table form _____.
Matter cannot be created or destroyed, but it can change forms
What is the Law of Conservation of Mass?
"salt-former," has 7 valence electrons, very reactive nonmetal
What are halogens?
Positively charged particle in the nucleus of an atom
What is a proton?
when an atom's electrons are in the lowest possible energy levels
What is ground state?
the number of protons in an atom
What is the atomic number?
currently accepted model of the atom
What is the electron cloud model?
Have one valence electron and extremely reactive; only exist in nature compounds; shiny and malleable
What are alkali metals?
a neutral particle in the nucleus of an atom
What is a neutron?
when an atom's electrons move to an orbital with higher energy; an unstable state
What is excited state?
Periods on the periodic table form _____.
What are rows?
Samples of a pure compound always have the same elements in the same mass proportion
What is the Law of Constant Composition?
Have 5 valence electrons; a wide range of physical qualities like the carbon group
What is the nitrogen group?
atoms of an element with the same number of protons but different numbers of neutrons
What are isotopes?
electrons that are in the highest energy level (the energy level farthest from the nucleus) of an atom of an element
What are valence electrons?
The sum of the protons and neutrons in the nucleus of an atom
What is the mass number?
another name for the electron cloud model of the atom
What is the quantum-mechanical model?
Have 3 valence electrons; solid at room temperature; "metalloid"
What is the boron group?