Vocabulary
Positively charged particles of an atom that are located in the nucleus.
What is a proton?
In 400 BC, this scientist developed the idea of the atom and called it atomos (uncuttable).
Who is Democritus?
All atoms of any given element have the same number of ________.
What is protons?
The elements in group 1 have ____ valence electrons.
What is 1 valence electron?
This element has the chemical symbol of C.
What is Carbon?
Identify how many groups and periods?
groups- 18 columns
periods- 7 rows
JJ Thomsom created this model with negative charged particles spread evenly throughout.
What is the Plum Pudding Model?
Which subatomic particle is found in the energy levels (shells)?
What are electrons?
The elements in each period share the same amount of
What is Shells?
Chemical symbol N .
What is Nitrogen?
The number of protons in an atom.
What is an atomic number?
Who made the first complete attempt to describe matter in terms of atoms?
Who is John Dalton?
The periods help us identify the amount of what?
energy levels of the atom (shells)
In the Periodic Table it is categorized in only 3 ways.
What is metals, nonmetals and metalloids?
Name the chemical symbol for Hydrogen.
What is H?
Electrons that in the highest energy level of an atom of an element.
What are Valence electrons?
Who conducted the gold foil experiment to discover the nucleus was the positively charged center of an atom?
Who is Ernest Rutherford?
The maximum number of electrons that can occupy the 2nd shell of an atom
8
sequence (2,8,8,18)
The elements in group 18 are called ______ , have ___ valence electrons (except helium), and are useful because they do not ______ with other elements.
What are Noble Gases, 8 valence electrons, and react?
This element has the chemical symbol of Al.
What is Aluminum?
Atoms of an element with the same number of protons but different numbers of neutrons.
What are isotopes?
Niels Bohr created this model that is seen the most often today.
What is the Electron Cloud model?
(Bohr's model)
Halogens are located in group ___?
What is 17?
The Russian chemist and teacher who first grouped elements together in a table by their properties was __________.
Who is Dmitri Mendeleev?
This element has the chemical symbol of Na.
What is Sodium?