This question seems to lack information. Please complete.
Their valency is one and both belong to the third period
Answer:
Alfred Lothar Wegener was a German polar researcher, geophysicist and meteorologist. During his lifetime he was primarily known for his achievements in meteorology and as a pioneer of polar research.
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.
