Chapter 17 Definitions Flashcards
What are atoms composed of?
Protons, neutrons, and electrons
What happens in 1897?
J.J Thomson discovers the electron (e-). e- has a negative charge.
Ernest Rutherford discovered the atom contains a positively charged core called the nucleus.
1911
Positive charge(p+) in the nucleus
Proton
Particle with no charge in the nucleus(n0)
Neutron
Very tiny and orbit the nucleus
Electrons
The number of protons found in an atom
Atomic number
Atoms of the same element with different numbers of neutrons.
Isotopes
What do isotopes do?
Give atoms of a single element different masses. C14, S33
Total number of protons and neutrons in the nucleus.
Mass number
What are elements named for?
Properties, locations, scientists, planets, Latin or Greek origins
Total mass of an atom. Mass of all protons, neutrons, and electrons.
Atomic mass
Atomic mass is measured in what?
(Amu) daltons. It takes 6x10 to the 23 Amu to equal one gram
What groups can the periodic table be divided into?
Metals and nonmetals
Shiny, opaque, malleable, ductile, and good conductors of heat and electricity.
Metals
Poor conductors, may be solids, liquids, or gases.
Nonmetals
Tells how many occupied energy levels are in each atom of an element. (Rows across)
Period
Elements with similar characteristics. (Columns down)
Group (family)
Left hand column of periodic table. (Li, Na, K…) most chemically reactive metals.
Alkali metals
Very reactive; form ionic bonds. (Ca, Mg, Be…)
Alkaline earth metals
The gradual change of any property in the elements across a period (size)
Periodic trend
Discovered by Rutherford in 1919. Process of adding a p+ to the nucleus of an atom.
Transmutation of elements
What are all the elements right of uranium?
Transmutated, they do not exist in nature.
What will transmutated elements do?
They break apart giving off excess protons and neutrons. These particles are radioactive.
