Atoms 2.0 Flashcards
What is the charge of an atom, and how?
Overall, the charge of an atom(not an ion)is always neutral as the number of electrons and protons are the same, cancelling each other out.
What else does an atom have?
An atom also has a lot of completely empty space/gaps between parts of the atom.
What is the relationship between positive and negative charges?
Positive and negative charges attract.
What is electrostatic attraction?
Electrostatic attraction is what holds the individual atom together, through attraction between the positive charge on the protons and negative charge on the electrons.
Who is JJ Thompson and what did he discover?
JJ Thompson, a British scientist, discovered the electron in the late 1890s and proposed a new model for the atom where electrons were scattered throughout the structure.
What was JJ Thompsons model of the atom called and why?
JJ Thompson’s model is called the ‘plum pudding’ model as the particles are arranged randomly throughout the model, like fruit in a pudding.
What all did JJ Thompsons model of the atom have and what did it not?
There is:
* uniform positive charge throughout the whole atom
* randomly arranged electrons
There is not:
* no nucleus
* no shells
* no protons
* no neutrons
* no empty space / gap
* orbiting electrons in shell
Who was Ernest Rutherford and what did he discover?
Ernest Rutherford, of Thompson’s students from New Zealand, discovered the proton in 1909 and nucleus in 1911.
What was Rutherford’s most famous experiment?
Rutherford’s most famous experiment was the gold foil experiment.
What happened in the gold foil experiment and what did it lead to?
Rutherford’s gold foil experiment involved firing fast-moving alpha particles at thin gold foil. Most passed through, but a few were deflected, leading Rutherford to conclude that most of the atom is empty space. The rare deflections (1 in 8000) indicated the presence of a small, dense, positively charged nucleus at the center of the atom.
