Shared Flashcard Set

Details

Science 4-1
Introduction to Atoms
15
Science
8th Grade
11/07/2011

Additional Science Flashcards

 


 

Cards

Term
atom
Definition
smallest particle of an element
Term
nucleus
Definition
center of an atom
Term
protons
Definition
positively charged particles inside the nucleus
Term
energy level
Definition
specific amount of energy it has; an electron's movement is related to its energy level
Term
neutron
Definition
electrically neutral particle
Term
isotopes
Definition
atoms with the same number of protons and different number of neutrons
Term
mass number
Definition
the sum of the protons and neutrons in the nucleus of an atom
Term
atomic number
Definition
unique number of protons in the nucleus of an atom
Term
electron
Definition
negatively charged particles
Term
What is the atomic theory?
Definition
Grew as a series of models that developed from experimental evidence. As more evidence was collected, the theory and models were revised.
Term

How was Chadwick's atomic model different from those in the past?

 

 

 

 

Definition
The modern model describes an atom as consisting of a nucleus that contains protons and neutrons, surrounded by a cloudlike region of moving electrons.  **Chadwick founded the neutron; neutrons were hard to detect before this because they had almost the same mass as a proton
Term
Explain Dalton's Atomic Theory. (4 steps)
Definition

1)  All elements are composed of atoms that cannot be divided

2)  All atoms of the same element are exactly alike and have the same mass.  Atoms of different elements are different and have different masses.

3)  An atom of one element cannot be changed into an atom of a different element.  Atoms cannot be created or destroyed in any chemical change, only rearranged.

4)  Every compund is composed of atoms of different elements, combined in a specific ratio.

Term
Where were the electrons located in Thomson's model of an atom?
Definition
Thomson said that electrons were scattered throughout the atom all over the place (like blueberries in a muffin)
Term
Explain Bohr's Model.
Definition
Bohr's model is different from Thomson's; Bohr said that electrons could only have certain orbits.  Electrons moved like planets orbiting the sun in his model (or like layers of an onion)
Term
Where were the electrons located in the modern model of the atom?
Definition
The modern model of an atom has a nucleus that contain protons and neutrons, surrounded by a cloudlike region of moving electrons.
Supporting users have an ad free experience!