Elements
The chemical symbol for Helium is what?
What is He
Stated electrons are fixed particles in specific orbits
Neils Bohr
Who invented the periodic table?
Who is Dimitri Mendeleev
The electrons on the outmost energy level are called______?
What is valence electrons
Isotopes are what?
What is atoms of the same element with different # of neutrons
The chemical symbol for Sulfur is what?
What is S
Stated atoms are indivisible
Democritus and Dalton
What doesthe atomic number represent?
What is # of protons
Where are electrons found?
What is electron cloud outside of the nucleus
What does the atomic mass represent?
What is average mass of the element
The chemical symbol for Oxygen is what?
What is O
First to prove that atoms are not indivisible.
JJ Thomson
How many electrons are in the 1st energy level of an atom?
What is 2 electrons
How is the periodic table organized
What is increasing number of protons
The atomic # for Cobalt
What is 58.93
The experiment that Rutherford used to discover the nucleus
Gold foil experiement
What are periods?
What are horizontal rows in periodic table
What charge does an electron have?
What is negative charge
Name an element that has similar properties to Florine
What is Cl, Br, I, or At
What is the atomic # for Xenon is what?
What is 54
Stated the atom's mass is concentrated in the center of the atom, and therefore, dense surrounded by a lot of empty space
Rutherford
Which elements are good conductors of heat and electricity?
What are metals
Where are quarks found?
What is Inside protons and nuetrons
What are metaliods?
What is properties of metals and nonmetal