the positively charged central core of an atom
Nucleus
a system for arranging the chemical elements
The Periodic Table
the elements found on the far right side of the periodic table
Helium, Neon, Argon, Krypton, Xenon, and Radon
elements that lose electrons easily, are lustrous, malleable, and are good conductors of heat and electricity
Metals
This scientist theorized, "All elements are composed of atoms that cannot be divided."
Dalton
a very small particle that exists in the nucleus of every atom and has a positive charge of electricity
Proton
inventor of the periodic table of elements
Mendeleev
Helium, Neon, Argon, Krypton, Xenon, and Radon are all known as...
Free sqaure!
Free points!
This scientist described an atom that consisted of negative charges scattered throughout a ball of positive charge- something like raisins or berries in a muffin.
Thomson
a very small particle that has a negative charge of electricity and travels around the nucleus of an atom
Electron
This arranges the elements in rows and columns. The columns form groups of elements that have similar chemical properties.
The periodic table
found on the far left side of the periodic table
Hydrogen, Lithium, Sodium, Potassium, Rubidium, Caesium, and Francium
elements that generally do not conduct electricity
Non-metals
This scientist inferred that an atom’s positive charge must be clustered in a tiny region in its center, called the nucleus.
Rutherford
a subatomic particle of about the same mass as a proton but without an electric charge
Neutron
a column of elements on the periodic table. Each column has the same number of valence electrons
Family
On the far right side of the periodic table, in group 18, is a unique group of elements called
Noble gases
Hydrogen, Lithium, Sodium, Potassium, Rubidium, Caesium, and Francium are all...
Alkali metals
This scientist showed that electrons could have only specific amounts of energy, leading them to move in certain orbits. The series of orbits in his model resemble planets orbiting the sun or the layers of an onion.
Bohr
the energy in the center (or nucleus) of an atom
Engergy level
any horizontal row of elements
Periods
all of these of a given element have the same number of protons but different numbers of neutrons in each atom.
Isotopes
a unique group of elements that share properties of both metals and nonmetals
Metalloids
This scientist determined that electrons do not orbit the nucleus like planets; instead they can be anywhere in a cloudlike region around the nucleus.
Schrödinger