1.2 Atomic Structure Flashcards
What is the first postulate of the John Dalton Theory?
Matter is made up of indestructible atoms.
This postulate emphasizes the fundamental concept of atomic theory.
What does the Law of definite proportions state?
Elements combine in a characteristic ratio.
This law indicates that a chemical compound always contains its component elements in fixed ratio by mass.
What is the Law of multiple proportions?
Some elements have more than one combining capacity.
This law describes how different compounds can form from the same elements in different ratios.
What does Dalton’s Theory say about the creation and destruction of atoms?
Atoms cannot be created nor destroyed.
This principle underlines the conservation of mass in chemical reactions.
What was J.J. Thomson’s model of the atom called, and what did it propose?
“The Raisin Bun Model”. It proposed that atoms were a mixture of electrons and protons, stuck together like raisins in a bun. This model was later proven incorrect.
What important subatomic particle did J.J. Thomson discover?
The electron.
What concept about atoms and electrons did J.J. Thomson’s work lead to the understanding of?
Atoms can gain or lose electrons to form ions.
According to J.J. Thomson, what determined the identity of an element?
Thomson incorrectly stated that the number of electrons determined the identity of an element. (The actual identity of an element is determined by the number of protons.)
What is the structure of the atom according to Rutherford’s model?
Atoms have a tiny, dense nucleus containing positively charged protons and neutral neutrons. This nucleus makes up most of the atom’s mass.
What is the charge of the nucleus in Rutherford’s model?
Positive
What subatomic particle occupies most of the volume of the atom?
The electrons.
What determines the identity of an element according to Rutherford?
The number of protons
