Dalton Solid Aphere? Flashcards
What is the basic unit of matter?
Atom
Who proposed the first atomic theory in the early 1800s?
John Dalton
True or False: Atoms can be divided into smaller particles.
False
What are the three main subatomic particles?
Protons, neutrons, and electrons
Fill in the blank: The nucleus of an atom contains ______ and ______.
protons; neutrons
Who discovered the electron?
J.J. Thomson
What model of the atom did J.J. Thomson propose?
Plum pudding model
Which scientist is known for the gold foil experiment?
Ernest Rutherford
What did Rutherford’s gold foil experiment demonstrate?
The existence of a dense nucleus
True or False: Rutherford proposed the planetary model of the atom.
True
What did Niels Bohr contribute to atomic theory?
The Bohr model, which introduced quantized orbits for electrons
Fill in the blank: The Bohr model of the atom is based on ______ principles.
quantum
What year did Niels Bohr publish his model of the atom?
1913
Multiple Choice: Which particle has a negative charge? A) Proton B) Neutron C) Electron
C) Electron
What is the charge of a proton?
Positive
What is the mass of a neutron compared to a proton?
Approximately the same
Fill in the blank: The atomic number of an element is determined by the number of ______ in its nucleus.
protons
Who developed the quantum mechanical model of the atom?
Erwin Schrödinger
True or False: Electrons are found in defined orbits in the quantum mechanical model.
False
What concept did Schrödinger introduce in relation to electrons?
Wave functions
What is the significance of the uncertainty principle?
It states that the position and momentum of a particle cannot be simultaneously known.
Fill in the blank: The uncertainty principle was formulated by ______.
Werner Heisenberg
Which model of the atom depicts electrons in probability clouds?
Quantum mechanical model
What does the term ‘isotope’ refer to?
Atoms of the same element with different numbers of neutrons
