The Atom Flashcards
(35 cards)
What do models provide about atoms?
Evidence for the existence of atoms + molecules.
What can models be used to represent?
1) Arrangement and motion of particles in different phases, and
2) Arrangement of and forces that bind protons, neutrons, and electrons in an atom.
Who were the four people who helped develop the current understanding of molecular theory?
- Dalton
- Thompson
- Rutherford
- Bohr
What are protons and neutrons made of?
Quarks
Protons and neutrons are held together in the nucleus by a _____?
The STRONG nucleus force.
The electron is a type of _____?
Lepton
How are the electrons held at a distance from the nucleus?
Through electromagnetism.
What is the key feature of the Dalton model?
The atom is…
1) indivisible, and
2) invincible.
What is the key feature of the Thomson model?
An atom contained NEGATIVELY charged particles called ELECTRONS.
What is the key feature of the Rutherford model?
The nucleus is the SMALL DENSE CENTRE of the atom.
What is the key feature of the Bohr model?
Electrons occupy SPECIFIC ENERGY LEVELS.
What is a quick description of JJ Thomson’s experiment?
Cathode rays (made of particles) are charged because they were BENT by MAGNETS.
What is the name of JJ Thomson’s experiment?
The Cathode Ray experiment.
What is a quick description of Rutherford’s experiment?
Alpha particles go through gold foil, and some are deflected.
What is the name of Rutherford’s experiment?
The Gold Foil experiment.
What is a quick description of Bohr’s experiment?
Light coming from atoms have certain amounts of ENERGY.
What is the name of Bohr’s experiment?
The Hydrogen Spectra experiment.
What is the conclusion of Thomson’s experiment?
Negative parts (electrons) are in atoms.
What is the conclusion of Rutherford’s experiment?
There is a small positive nucleus.
What is the conclusion of Bohr’s experiment?
Electrons are in specific energy shells.
How are quarks and leptons related to protons, neutrons, and electrons?
Electrons are a flavour of leptons. Protons and neutrons are made of quarks.
Compare and contrast a proton and a neutron.
Protons are positively charged but neutrons are neutral. Both are in the nucleus. They are a similar mass. Both are made of quarks.
Briefly explain why Thomson’s experiments lead to Dalton’s model being revised.
Thompson’s experiment showed atoms have charged particles and were not solid and indivisible.
Explain the difference between the terms subatomic particle and elementary particle.
Subatomic particles are components of atoms, such as protons, neutrons and electrons. Elementary particles cannot be broken down into smaller pieces. Only electrons are both subatomic and elementary particles.
