Atomic Vocabulary
dense, massive core of the atom
What is the nucleus?
All atoms in the same group have the same number of these
What are valence electrons?
Greek who gave us the name atom
Who is Democritus?
the lightest and most common element in the universe
What is hydrogen?
All elements in the same period have this in common
What are electron shells or energy levels?
voluminous area where we find electrons
What is electron cloud?
Atoms in this group are not very reactive
What are the noble gases?
he used the gold foil experiment to discover the dense, positively charged nucleus
Who is Rutherford?
This noble gas is used to inflate balloons
What is helium?
Table that organizes elements by properties
What is the periodic table?
Atoms of elements that contain different numbers of neutrons
What are isotopes?
Elements in this group are the most reactive metals
What are alkali metals?
Constructed the first periodic table.
Who is Mendeleev?
This element with 4 valence electrons is the building block of life on earth
What is carbon?
The sum of all protons and neutrons in an element
What is mass number?
Atoms of elements which contain different numbers of electrons
What are ions?
Elements in this group are the most reactive nonmetals
What are the halogens?
Developed the electron cloud model with different energy shells
Who were Heisenberg and Schrodinger?
This element with 5 valence electrons makes up 78% of earth's atmosphere
What is nitrogen?
Vertical columns
What are groups?
Elements are defined by the number of these
What are protons?
Sc and Y are elements in this family
What are the rare earth metals?
Developed model that has electrons in fixed orbits about the nucleus.
Who is Bohr?
This light metal with 3 valence electrons is commonly used in cans
What is aluminum?
The smallest form of matter that retains the properties of an element
What are atoms?