The energy balance in a thermodynamic process is expressed in the ______________.
Fill in the blank(s) with correct word
[Ques. 2] How many radioactive atoms are present in a sample that has an activity of 0.5 Ci and a half-life of 10 years? (1 curie = 3.7 1010 decays/s)
a. 9.5 1012 atoms
b. 8.4 1012 atoms
c. 7.3 1012 atoms
d. 6.5 1012 atoms
e. 2.7 105 atoms
[Ques. 3] The elapsed time between two successive crossings of the same meridian by a star other than the Sun is known as
a. the tropical year.
b. one sidereal day.
c. the sidereal year.
d. none of these.
[Ques. 4] The first law of thermodynamics states that heat added to a closed system can change the internal energy of the system and/or do ______________.
Fill in the blank(s) with correct word
[Ques. 5] The half-life of 131I is 8.04 days. Three days after it was prepared, its activity was 0.50 Ci. How many curies (in Ci) were initially prepared?
a. .60
b. .70
c. .65
d. .55
e. .39
[Ques. 6] The farthest point of the Sun from the equator is known as the
a. declination.
b. solstice.
c. latitude.
d. equinox.
[Ques. 7] For an ideal gas with N and T held constant, an increase in volume will result in a(n) ______________ in pressure.
Fill in the blank(s) with correct word
[Ques. 8] 44 g of petrified wood was found in a petrified forest. A sample showed a 14C activity of 100 decays/minute. How long has the tree been dead (in years)? (The half-life of carbon-14 is 5730 years and freshly cut wood contains 6.5 1010 atoms of 14C per gram.)
a. 12300
b. 15600
c. 8500
d. 4700
e. 2400
[Ques. 9] The time interval from one vernal equinox to the next is called one ______________ year.
a. sidereal
b. celestial
c. solar
d. tropical
[Ques. 10] If the volume and the number of molecules remain constant for a gas, a temperature increase causes the pressure to ______________.
Fill in the blank(s) with correct word
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