18 questions
When a decimal point is present, start from the...
first non-zero # on the left and move to the right.
first non-zero # on the right and move to the left.
When a decimal point is absent, start from the...
first non-zero # on the left and move to the right.
first non-zero # on the right and move to the left.
How many significant figures are present: 306.4000
4
7
3
How many significant figures are present: 20.00
4
1
3
How many significant figures are present: 200.00
4
1
5
How many significant figures are present: 0.004
4
1
5
How many significant figures are present: 1200
4
1
2
How many significant figures are present: 120
3
1
2
How many significant figures are present: 12
3
1
2
How many significant figures are present: 1207
3
1
4
Atomic Theory: Democritus is credited with..
the first idea of the existence of the atom.
the 4 postulates.
the discovery of an electron.
the gold-foil experiment.
Atomic Theory: John Dalton is credited with..
the first idea of the existence of the atom.
the 4 postulates.
the discovery of an electron.
the gold-foil experiment.
Atomic Theory: J.J. Thompson is credited with..
the new atomic model.
the 4 postulates.
the discovery of an electron.
the gold-foil experiment.
Atomic Theory: Ernest Rutherford is credited with..
the new atomic model.
the 4 postulates.
the discovery of an electron.
the gold-foil experiment.
Atomic Theory: Niels Bohr is credited with..
the new atomic model.
the 4 postulates.
the discovery of an electron.
the gold-foil experiment.
Atomic Theory: Which one is true of Dalton's 4 postulates? (check all that apply)
Atoms are neither created nor destroyed.
Elements are made of small/indivisible particles called atoms.
Chemical reactions occur when atoms are combined, separated, or rearranged in simplified whole-number ratios.
Atoms of an element are identical to one another, but differ from atoms of other elements.
Atomic Theory: The image of a Cathode Ray Tube shows that...
the light passing through is repels the negative end of a magnet, proving that there are electrons.
the light passing through is repels the negative end of a magnet, proving that there are protons.
Atomic Theory: The Gold-Foil Experiment shows alpha (+) particles bouncing off the center of the gold atom, this shows...
that the nucleus contains protons that repel the alpha particles.
that the nucleus contains electrons that attract the alpha particles.