Vocabulary
This law states mass is not created or destroyed in a chemical reaction.
What is the Law of Conservation of Mass?
He named tiny indivisible particles “atomos.”
Who is Democritus?
The particle with a positive charge.
What is a proton?
Who first created the periodic table by arranging elements by properties?
Who is Mendeleev?
Group 1 of the periodic table, very reactive metals.
What are the alkali metals?
This law states that compounds always contain the same elements in the same proportions.
What is the Law of Constant Composition?
He believed everything was made of four elements: earth, fire, air, and water.
Who is Aristotle?
The particle with a negative charge.
What is an electron?
Today’s periodic table is arranged by increasing ________.
What is atomic number?
Group 2 of the periodic table, less reactive but still metals.
What are the alkaline earth metals?
The number of protons in an atom is called this
What is the atomic number?
His “Plum Pudding” model showed electrons in a positive sphere.
Who is Thomson?
The particle with no charge.
What is a neutron?
The vertical columns in the periodic table are called ________.
What are groups (or families)?
Group 17 of the periodic table, includes chlorine and fluorine.
What are the halogens?
The total number of protons plus neutrons in an atom.
What is the mass number?
His gold foil experiment proved atoms have a dense nucleus.
Who is Rutherford?
The electrons in the outermost energy level.
What are valence electrons?
The horizontal rows in the periodic table are called ________.
What are periods?
Group 18 of the periodic table, unreactive gases.
What are the noble gases?
Atoms of the same element with different numbers of neutrons.
What are isotopes?
He discovered the neutron.
Who is Chadwick?
Areas where electrons are most likely to be found.
What are orbitals?
Elements in the same group share similar ________.
What are properties (or chemical behaviors)?
The group that contains carbon, the element of life.
What is the carbon group?