A certain substance has a half-life of 5.0 hours. How many nuclei of the substance are required to give an initial activity of 6.0 ?Ci? 1 Ci = 3.7 × Bq
A) 5.8 × 109
B) 8.5 × 108
C) 6.3 × 108
D) 3.2 × 109
E) 2.4 × 109
Answer: A
You might also like to view...
Thermodynamic Processes: The figure shows a pV diagram for 0.98 mol of ideal gas that undergoes the process 1 ? 2. The gas then undergoes an isochoric heating from point 2 until the pressure is restored to the value it had at point 1. What is the final temperature of the gas? (R = 8.31 J/mol ? K).
A. -160°C B. 12°C C. 380°C D. 110°C
A dragster drives a quarter mile (402 m) at a constant rate of acceleration, starting from rest and finishing the race at a final speed of 450 km/hr. If the mass of the dragster is 975 kg, together with its driver, and rolling friction is ignored, what average power was developed by the engine, if 50% of the power developed by the engine was delivered to the wheels?
A. 4.7 MW B. 1.2 MW C. 0.6 MW D. 2.4 MW
What does temperature measure?
A) the average kinetic energy of particles in a substance B) the average mass of particles in a substance C) the total potential energy of particles in a substance D) the total amount of heat in a substance
What defines the habitable zone around a star?
A) the region around a star where rocky planets can form B) the region around a star where humans can survive C) the region around a star where liquid water can exist on planetary surfaces D) the region around a star where its ultraviolet radiation is too weak to destroy biological organisms on a planetary surface E) the region around a star outside of its hot, tenuous corona