the atom Flashcards
what are the 3 subatomic particles?
proton, neutron, & electron.
what are the charges of the 3 subatomic particles?
proton +1, neutron 0, & electron -1.
what are the locations of the 3 subatomic particles?
proton & neutron in the nucleus; electron in orbitals/shells
what is the net charge of the a carbon nucleus
+6
what does the Atomic number tell us?
the number of protons in an atom’s nucleus and determines the identity of an atom.
what can be said about the number of protons and electrons in an atom
they are equal
what is the mass number
protons + neutrons
what are isotopes?
atoms of the same element that have the same number of protons but different number of neutrons
what is the difference between isotopes
number of neutrons
how can you determine the number of neutrons in an atom?
subtract the atomic number from the mass number
what does the 14 mean in carbon-14 ?
the mass number
what is atomic mass?
weighted average based on the natural abundance of isotopes
what was discovered for the plum-pudding model
cathode ray particles (electrons)
what important experiment did Rutherford perform?
gold foil experiment
what 2 important conclusions came from the gold foil experiment?
1 Most of an atom is empty space.
2 Most of an atom’s mass is concentrated in a dense, positively charged nucleus.
what was new about the Bohr model?
energy levels
Discuss energy levels in terms of distance from the nucleus and energy.
1st PEL less energy, closest to the nucleus
2nd PEL more energy, further from the nucleus
How are spectral lines formed?
When an electron falls from the excited state to the ground state it emits light energy in the form of spectral lines.
Where are electrons located in the wave mechanical model?
In orbitals
What are valence electrons?
The electrons in the outermost energy level
Is 2-7-3 ground or excited? For what element?
excited Mg
What are the masses of protons, neutrons, and electrons?
protons 1, neutrons 1, and electrons almost zero
