History Of Atom Flashcards
(15 cards)
What is the basic unit of matter that makes up all substances?
An atom
Who proposed the first atomic theory in the early 1800s?
John Dalton
True or False: Dalton’s atomic theory stated that atoms are indivisible and indestructible.
True
What discovery did J.J. Thomson make in 1897?
The electron
Fill in the blank: The model of the atom proposed by Thomson is known as the __________ model.
Plum pudding
Who conducted the gold foil experiment in 1909?
Ernest Rutherford
What was the main conclusion of Rutherford’s gold foil experiment?
Atoms have a small, dense nucleus.
Which scientist proposed the planetary model of the atom?
Niels Bohr
True or False: Bohr’s model suggested that electrons travel in fixed orbits around the nucleus.
True
What concept did the quantum mechanical model of the atom introduce?
Electron clouds or probability distributions
Who developed the quantum mechanical model of the atom?
Erwin Schrödinger
Multiple Choice: Which of the following particles is found in the nucleus of an atom? A) Electron B) Proton C) Neutron D) Both B and C
D) Both B and C
What are isotopes?
Atoms of the same element with different numbers of neutrons.
Fill in the blank: The atomic number of an element is determined by the number of __________ in its nucleus.
Protons
True or False: The mass number of an atom is the sum of protons and electrons.
False
