Final answer:
To find the speed of the lead-206 nucleus in alpha decay, we can use the conservation of momentum and solve for its velocity using the equation momentum = mass x velocity.
Step-by-step explanation:
In alpha decay, a stationary nucleus emits an alpha particle. The initial speed of the alpha particle is not provided in the question. However, we can determine the speed of the resulting lead-206 nucleus.
To find the speed of the lead-206 nucleus, we can use the conservation of momentum. In alpha decay, the total momentum before and after the decay remains the same.
Since the initial nucleus is stationary, its momentum is zero. Therefore, the momentum of the alpha particle before the decay is equal to the momentum of the lead-206 nucleus after the decay. By using the equation:
momentum = mass x velocity
we can solve for the velocity of the lead-206 nucleus.