Shared Flashcard Set

Details

Chapters 5 and 8
Atoms/fission/fusion/scientists
16
Chemistry
10th Grade
10/21/2010

Additional Chemistry Flashcards

 


 

Cards

Term
What did Democritus do as a scientist and when?
Definition
400 BC- He was the first one to suggest existence of atoms.
Term
Who was John Dalton, and name one of his correct theories?
Definition

He was an English teacher who studies ratios in which elements combined in chemical reactions. Correct theories:

-Atoms of the same element are identical

- All elements have indivisible, tiny particles called atoms.

Term
What is the relative size of atoms?
Definition
100,000,000 Cu atoms placed side by side are no longer than 1 cm!!
Term
What is the charge of any atom and why?
Definition
Neutral, because if it wasn't, objects would shock us everytime we touch them!
Term
Who was JJ Thompson?
Definition
He discovered the existence of the electron.
Term
What did Robert Millikan do?
Definition
He calculated the mass of electrons.
Term
What did E. Goldstein discover and how?
Definition
He found protons by studying cathode ray tubes.
Term
What did James Chadwick do?
Definition
He confirmed the existence of the neutron.
Term
*What did Ernest Rutherford do?
Definition
He tested the theory of atomic structure, but using a gold foil experiment. He concluded that most of an atom is empty, with a dense, positive nucleus.
Term
What is the atomic number of an element?
Definition
The number of protons in the atom.
Term
The number of protons=
Definition
The number of electrons.
Term
What is the mass number of an element?
Definition
The number of protons + the number of neutrons.
Term
*What is an isotope?
Definition
Atoms that have the same number of protons but a different number number of neutrons.
Term
The atomic mass=
Definition
the average of isotopes.
Term
**Who was Mendeleev and who was Mosely? Which way is the periodic table set up today?
Definition

Mendeleev- 1st arranged elements in a table (BY ATOMIC MASS). Predicted properties of elements not yet discovered.

 

*Moseley- (ARRANGED BY ATOMIC NUMBER) We use MOSELEYS TABLE (THE PERIODIC TABLE TODAY)

Term
How did the periodic table get its name?
Definition
Because of elements arranged periodically by properties.
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