+
Related Flashcards
Related Topics
Cards In This Set
| Front | Back |
|
Who is responsible for developing the first model of the atom?
|
Greek philosophers
|
|
What did Empedocles state?
|
That all matter was composed of four "elements"-fire, water, air, and earth
|
|
__________thought that all forms of matter were compposed of tiny indivisible particles which he called atoms.
|
Democritus
|
|
What did Democritus do?
|
He held that atoms were in constant motion and that they combined with one another in various ways. This hypothesis was not based on scientific observations
|
|
After Democritus, ____________, opposed the theory of Democritus and instead endorced and adavanced the Empedoclean theory.
|
Aristotle
|
|
What did Aristotle do?
|
Dominated the thinking of scientists and philosophers until the beginning of the 17th century.
|
|
Who revived the concept of atoms and proposed an atomic model based on facts and experimental evidence. He came nearly 2000 years after Democritus?
|
John Dalton, an English school teacher
|
|
What did Dalton's theory describe?
|
The idea of a different kind of atom for each element
|
|
How can Dalton's atomic modeel be summed up?
|
1. Elements are composed of minute, indivisible particles called atoms
2. Atoms of the same element are alike in mass and size 3. Atoms of different elements have different masses and sizes 4. Chemical compounds are formed by the union of tow or more atoms of different elements 5. Atoms combine to form compounds in simple numerical ratios such as one to one, one to two, two to three and so on 6. Atoms of two elements may combine in different ratios to form more than one compound |
|
Why was Dalton's atomic model significant even though it was later proven to be incorrect?
|
It showed:
1. atoms are composed of subatomic particles 2. not all the atoms of a specific element have the same mass 3. atoms, under special circumstances, can be decomposed |
|
In chemistry, what are models used for?
|
To explain the behavior of atoms, molecules, and compounds. To explain new information
|
|
What is a natural law?
|
General observations regarding nature into a statement
|
|
What is the law of definite composition?
|
A compound always contains two or more elements chemically combined in a definite proportion by mass
|
|
What is the law of multiple proportions?
|
Atoms of two or more elements may combine in different ratios to produce more than one compound
|
|
The law of multiple proportions states________________.
|
1. the composition of a particular substance will always be the same no matter what its origin or how it is formed
2. the composition of different compounds formed from the same elements will always be unique |
