By the time the Universe was about two minutes old, protons and neutrons could link to form _____, the nucleus of a heavy hydrogen atom, and not be broken apart again
A) uranium
B) helium
C) nitrogen
D) deuterium
D
You might also like to view...
A dime is 1.8 cm in diameter. At what distance from your eye would you have to hold a dime so that it has the same angular diameter as the full moon
a. 2 m b. 2 cm c. 2 km d. 2 inches e. 2 ft
A cloud fragment too small to form a star becomes:
A) a red giant. B) a black hole. C) a brown dwarf. D) a T Tauri object. E) a Herbig Haro object.
A heat-conducting rod that is wrapped in insulation is constructed with a 0.15-m length of alloy A and a 0.40-m length of alloy B, joined end-to-end
Both pieces have cross-sectional areas of 0.0020 m2. The thermal conductivity of alloy B is known to be 1.8 times as great as that for alloy A. The end of the rod in alloy A is maintained at a temperature of 10°C, and the other end of the rod is maintained at an unknown temperature. When steady state flow has been established, the temperature at the junction of the alloys is measured to be 40° C, and the rate of heat flow in the rod is measured at 56 W. What is the thermal conductivity of alloy A? A) 120 W/m ? K B) 125 W/m ? K C) 130 W/m ? K D) 135 W/m ? K E) 140 W/m ? K
Approximately how many half-life periods must elapse if the activity of a radioactive isotope sample is to be reduced to 0.03 of the original value?
a. 5 c. 8 b. 3 d. 60