Answer: alpha
Explanation: Alpha particles are fast moving streams of positively charged particles that are shown to be Helium nuclei. They have a mass
number of 4 and an atomic number of 2 and a charge of +2. Alpha particles are represented as 4He2. When 238U92 becomes 234Th90, it emitted a helium nucleus 4He2. The equation for the decay is 238U92 ---> 234Th90 + 4He2.
C because a lesion is high density
Answer:
The crust forms at the ridge and is carried away by the movement of the plate as new crust forms to take its place. The oceanic crust is youngest new a mid ocean ridge and oldest far away from it.
Explanation: