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Science Chapter 9 Review

Terms in this set (34)

What did Democritus believe about atoms?
they were indivisible and indestructible
if the object has a certain trait the atoms has that same trait
What did Aristotle believe about atoms?
He didn't believe in atoms and thought matter was made up of combinations of earth, air, water, and fire
Whose idea was accepted
Aristotles
What did John Dalton think a model looked like
He thought that all atoms were solid spheres
What did JJ Thomson think an model looked like
He thought it was a positively charged sphere with neutrons embedded in it (Plum pudding model)
What did Ernest Rutherford think an model looked like
He thought that the atom had a nucleus and that the electrons were circling the nucleus all the same distance away (Jimmy neutron model)
What did Erwin Schrödinger think an amodel looked like
That the position of electrons were uncertain and the nucleus is made up of protons and neutrons found in orbitals/energy levels- it got thicker in the predicted places
What are the basic points of Dalton's modern atomic theory
- Atoms cannot be divided, created, destroyed, or converted into atoms of another element.
- All atoms are identical to each other.
- All atoms are different from atoms of another element, and atoms combine in different ratios
What is the cathode ray tube, and what was discovered
(JJ Thompson) He placed two oppositely-charged electric plates around the cathode ray. The cathode ray was deflected away from the negatively-charged electric plate and towards the positively-charged plate.
What is the gold foil experiment, and what was discovered
Ernest Rutherford sent alpha particles through a thin sheet of gold foil and surrounded it with phosphorus and most went through but some bounced off so he believed that there was a nucleus
What particle did James Chadwick discover
Neutrons
What were the three main particles in atoms
Protons, electrons, and neutrons
Where are protons located
nucleus
Where are neutrons located
nucleus
Where are electrons located
Electron cloud surrounding the nucleus
Relative mass of a proton
+1
Relative mass of a neutron
+1
Relative mass of electron
1/1840
Charge of a proton
+1
Charge of a neutron
0
Charge of a electron
-1
What is a quark
a type of elementary particle and a fundamental constituent of matter
What is a isotope
An atom of an element that has a different number of neutrons
What is the atomic number
The number of protons in a element
What is the atomic mass
The number of protons and neutrons in an atom
What is a ion
Atom that has gained or lost one or more electrons
What happens with a atom that is radioactive
The particles and energy become unstable
What is special about Henri Becquerel and Pierre and Marie Curie
They discovered radioactivity
What are the three types of decay
Alpha, Beta, and Gamma
What happens with alpha decay
loss of 2 protons and 2 neutrons
What happens with beta decay
The neutron changes to proton and loses electron
What happens with gamma decay
When unstable atomic nuclei dissipate excess energy by a spontaneous electromagnetic process
What is radiation made of
Particles and energy from an atom
Good things about radiation
It can kill off cancer cells
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