Early Ideas About Atoms
“This Greek thinker first said that matter is made of tiny, unbreakable parts called ‘atomos.’”
“Who is Democritus?”
The experiment by Thomson, conducted in 1897, used these special tubes to show that tiny, negative particles exist in atoms.
What are Cathode Ray Tubes?
In 1909, scientists fired alpha particles at a thin foil and observed unexpected deflections, which led to a new model of the atom. What is the name of this experiment?
What is Rutherford’s gold foil experiment?
n 1913, this scientist explained that electrons travel around the nucleus in fixed paths called energy levels.
Who is Niels Bohr?
Atoms are made of three main parts. One of these is a positively charged particle found in the center. What is it?
What is a Proton?
“This famous thinker did not believe that empty space could exist, so he rejected the idea of tiny particles.”
Who is Aristotle?
Thomson found these tiny, negatively charged parts inside atoms.
What are electrons?
During this experiment, most alpha particles went straight through the foil. What does this suggest about the atom’s structure?
What is that the atom is mostly empty space?
Bohr’s model was supported by the light patterns seen when this simplest element is heated.
What is hydrogen?
his strong force holds the tiny protons and neutrons together in the nucleus. What is it called?
What is a nuclear force?
This teacher and scientist did experiments in the 1800s to show that matter is made of small particles called atom
Who is John Daulton?
homson proposed a model of the atom where electrons are spread throughout a positively charged substance. This model was nicknamed after a dessert. What is it called?
What is the Plum Pudding or Blueberry Muffin Model?
Only a few alpha particles bounced back from the foil. What discovery did this small number of deflections lead to?
What is the discovery of a small, dense nucleus?
When electrons change their energy levels, they release energy as this visible effect.
What is light?
A proton is made up of three quarks. Which quarks make up a proton?
What are two up quarks and one down quark?
The word ‘atomos’ comes from Greek. What does it mean?
What is uncuttable?
In his experiment, what did Thomson use to change the path of the cathode rays?
What are magnets and charged plates?
If the nucleus is the size of a hockey puck, what analogy could you use to describe the overall size of the atom
What is the arena?
Bohr compared the steps that electrons can jump between to the rungs of what common object?
What is a ladder?
A neutron is also made of three quarks. Which quarks are found in a neutron?
What are one up quark and two down quarks
According to Dalton, atoms join together in simple, small-number groups to form these types of new substances.”
What are compunds?
In Thomson’s plum pudding (blueberry muffin) model, what charge did he assign to the ‘muffin’ part that held the electrons?
What is positive?
The particles that bounced back showed that the nucleus contains parts with a positive charge. What are these positively charged particles?
What are protons?
The specific colors of light produced when electrons jump between energy levels are known as these.
What is the Spectrum?
Protons and neutrons are built from even smaller parts called what?
What are quarks?