Concept 1-3 Notes. Structure of the Atom Questions and Answers 100% Accurate

Concept 1-3 Notes. Structure of the
Atom

Atom - answer The smallest particle of an element that has the properties of that
element

Proton - answer(p+) Positive particle in the nucleus

Neutron - answer(n0) Neutral particle in the nucleus with protons

Electron - answer(e-) Negative particle outside of the nucleus in the electron cloud

Quarks - answer smallest known particles that makes up p+ and n0

Valence Electrons - answerElectrons on the outermost energy level of an atom

Atomic Number - answerTells the number of p+ in an atom of the element. Used to
identify an element Periodic table arranged by these.

Mass Number - answerNot on the periodic table Tells the number of protons & neutrons
in the nucleus of an atom ( where most of its mass is located)

Isotopes - answerAtoms of the same element with different numbers of neutrons

Average Atomic Mass - answerWeighted average of all the isotopes of an element;
closest to the most common isotope of the element

Groups/Families - answerThe vertical columns in the periodic table; contain elements
with similar chemical properties and the same number of valence electrons ( skipping 3-
12)

Periods - answerHorizontal rows on the periodic table; every element in that row has the
same number of energy levels (shells)

Democritus (400 BC) - answerFirst to name the atom

John Dalton (1803) - answerHe believed that an atom is a solid sphere that can get any
smaller. Elements are made of atoms that all have the same mass and compounds are
atoms of different element combined.

Dmitri Mendeleev (1869) - answerDeveloped the first periodic table of elements,
organized by atomic mass