The scarcity of what isotope is a critical test of the density of the present cosmos?

A) carbon 14
B) deuterium
C) helium 3
D) helium 4
E) lithium 5


B

Physics & Space Science

You might also like to view...

Which of the following materials is most appropriate for a design requiring a material with a high magnetic susceptibility that will be subjected to an alternating magnetic field of 10 6 Hz?

(a) Fe-3 wt. % Si (b) MnO (c) Alnico-5 (d) Fe3O4

Physics & Space Science

You want to insert an aluminum rod, which at 20°C has a radius of 1.000200 cm into a copper tube which has a radius of 1.000100 cm at the same temperature. You decide to put both of them in the refrigerator

At what temperature will the rod just fit if both are cooled to the same temperature? The coefficient of thermal expansion for aluminum is 2.4 × 10-5 K-1, and that of copper is 1.7 × 10-5 K-1. A) 6.3°C B) 7.8°C C) 9.2°C D) 5.7°C E) 15°C

Physics & Space Science

The reason a nuclear reactor will not explode like a bomb is because ________

a. the uranium-235 enrichment is too low. b. there is not enough uranium-238 present. c. the cooling water will always take away the heat d. there are control rods present e. …nonsense! It can explode like a bomb in the event of a loss of coolant accident

Physics & Space Science

Latitude Lines Run

What will be an ideal response?

Physics & Space Science