Dalton's Atomic Theory
What is the main premise of Dalton's atomic theory regarding matter?
Indivisible atoms.
What are the three main types of subatomic particles?
Protons, neutrons, electrons.
Who discovered the electron?
J.J. Thomson.
What is the charge of a neutron?
Neutral.
The weighted average mass of an element's isotopes.
atomic mass
How did Dalton's theory describe atoms in terms of indivisibility?
Cannot be created nor destroyed
What is the charge of a proton?
Positive (+1).
What experiment discovered the nucleus?
Gold foil.
How is mass number calculated?
Protons plus neutrons.
How is neutron number calculated?
subtracting the atomic number from the atomic mass
Name one major limitation of Dalton's atomic theory that was later revised.
Atoms can be divided into smaller particles (subatomic particles).
Where are protons and neutrons located?
Nucleus
Which particle did James Chadwick discover?
Neutron.
What role do electrons play in bonding?
Form bonds (being shared or transferred)
What is the atomic number of potassium?
19
What happens in a chemical reaction concerning atoms?
Atoms are rearranged (but their structure remains unchanged)
How does the mass of a neutron compare to that of a proton?
Approximately equal.
What did the gold foil experiment reveal?
Dense nucleus.
Compare the stability of protons and electrons.
Protons are more stable (It is stable in the nucleus, while electrons can be lost or gained during reactions.)
Which subatomic particle defines the atomic number?
Proton.
How did Dalton's atomic theory influence modern models?
Lead to the development of modern atomic theories.
Most noble gases have how many valence electrons?
8
What did Millikan's experiment measure?
Electron charge.
What are isotopes?
Atoms of the same element with different numbers of neutrons (different mass numbers)
How many protons are in a sodium atom?
Eleven.