This Greek philosopher was the first to propose that matter is made up of tiny, indivisible particles called atoms.
Who is Democritus?
The region around the nucleus where electrons are likely to be found is called the __________ cloud.
What is the electron cloud?
The atomic number of an element tells you how many of these particles are in the nucleus.
What are protons?
The smallest of the three main subatomic particles is the _____________
What is the electron?
In a chemical reaction, atoms rearrange to form ____________
What are new substances (or compounds)?
This scientist developed the solid sphere model of the atom.
Who is John Dalton?
The Bohr model shows electrons moving in fixed ______ around the nucleus.
What are orbitals?
The mass number is found by adding the number of protons and ______
What are neutrons?
The proton has this type of charge.
What is positive?
This model of the atom represented it as a solid, indivisible ball.
What is the solid sphere model?
Using the Crookes tube, this scientist discovered the electron.
Who is J.J. Thomson?
This principle states that it's impossible to know both the position and velocity of an electron at the same time.
What is the Heisenburg Uncertainty Principle?
Carbon has this many protons in its nucleus.
What is 6?
The atomic nucleus is positively charged because it contains these particles.
What are protons?
Rutherford discovered the __________ based on results from his Gold Foil experiment, and then later he also discovered the __________.
What is the nucleus and proton?
This scientist's gold foil experiment led to the discovery of the nucleus.
Who is Ernest Rutherford?
In the quantum mechanical model, electrons have a high probability of being found in these regions around the nucleus.
Aluminum has an atomic mass of approximately 26.982 amu. How many neutrons does it have?
What is 14?
Charged particles found in the atom include which two subatomic particles?
What are protons and electrons?
This scientist discovered the neutron.
Who is James Chadwick?
This scientist developed mathematical equations for the quantum mechanical model, describing electrons in clouds or orbitals instead of fixed paths.
Who is Erwin Schrodinger?
A scanning tunneling microscope allows scientists to do this.
What is view surfaces at the atomic level?
Two atoms of the same element with different numbers of neutrons are called__________
What are isotopes?
Hydrogen is unique among elements because its most common isotope has no_________________
This atomic model best explains the unpredictable position or movement of electrons.
What is the quantum mechanical model?