sig figs
which has the greatest # of sig figs?
a) 42,000 mL
b) 0.00052 cm
c) 0.7000 ds
d) 450 g
e) 9.30 x 10^-2 mm
c) 0.7000 ds (4 sig figs)
How many mL are in 4.75×10^2 L?
4.75×10^5 mL
Calculate the frequency of light with a wavelength of 600. nm.
5.00×10^14 Hz
a student needs to convert a measurement of 5.1 mg/m3 to g/cm3. what conversion factors are needed to accomplish this?
(provide 2 answers)
(10^-3 g / 1 mg) and (10^-2 m / 1 cm)^3
12.45+3.2+0.678
16.3
Convert 6.25 × 10⁻⁴ kg to mg.
6.25×10^2 mg
A radio wave has a frequency of 8.50×10^7 s^−1.
What is its wavelength in meters?
3.53 m
a technician can polish 12mm2 of a telescope lens every 95 s. how long, in minutes, will it take to polish the whole lens that has an area of 164 cm2 ?
report your answer to the correct sig figs.
2163.89 min, 2200 min with sig figs
report the answer to the correct number of sig figs.
22.82 + (2.21 X 3.04)
29.54
A city has an area of 125.0 mi². Using 1 mi=1.60934 km, what is the area in km²?
323.6 km^2
An electron in a hydrogen atom moves from:
n=2 → n=5
Is this absorption or emission of a photon?
Bonus: Does the electron gain or lose energy?
Absorption, gains energy
many elements have 2 naturally occurring isotopes. in which pair of isotopes is the heavier isotope more abundant than the lighter one?
a) 33Cl and 37Cl
b) 38Ar and 40Ar
c) 63Cu and 65Cu
d) 121Sb and 123Sb
b) because the weight of Ar on the periodic table is 39.948 g/mol.
report the answer to the right number of sig figs.
(112.52 - 64.388) X 0.230
11.1
if someone can run 10 kilometers in 1 hr, how many meters can they run in a day (assuming they run at the same pace)?
2 x 10^5 m
A laser emits a pulse of light with a wavelength of 650 nm. The total energy of the pulse is 0.0200 mJ.
Calculate the number of photons contained in the pulse.
6.53 x 10^13 photons
a nitrogen gas laser pulse with a wavelength of 337 nm contains 3.83 mJ of energy. how many photons does it contain?
6.49 x 1015 photons
A student measures the mass of an unknown metal sample as 24.63 g. The sample is placed into a graduated cylinder containing 35.0 mL of water, causing the water level to rise to 38.7 mL. What is the density of the metal? Report with correct sig figs.
6.7 g/mL
how many cubic yards are equivalent to 168.3 in^3?
1 yd = 36 in
3.607x10^-3 yd^3
Calculate the wavelength, in nm, of light with a radiation frequency of 4.741 x 10^14 Hz.
How much energy, in J, is carried by one photon of this radiation?
632.8nm, 3.143 x 10^-19 J
what is the frequency of an x-ray that has a wavelength of 1.00 Angstrom?
(1 Angstrom = 1 x 10-10 m)
then, calculate the total energy of 0.65 mol of x-ray photons.
3.00 x 1018 Hz, 7.8 x 108 J