A, radium-228. Alpha radiation is essentially just two protons and two neutrons leaving the atom, causing the atomic number to drop by two (since the protons left) and the mass number to drop by four (since two neutrons and protons left).
Answer:
Periods have consecutive atomic number as they are in a row and groups are vertical meaning they are in a column and groups have similar properties
Answer:
Explanation:
By definition, the momentum is given by:
p=m*v
Where,
m: car mass
v: speed of the car
Substituting the values in the given definition we have:
p=3*154
Answer:
the momentum of the car is:
4620g * cm/s
Answer:
A neutral particle made of an electron and hole
Explanation:
Exciton
It is the combination of an electron and a hole ( hole refers to the vacancy of an electron ) . And , as both the electron and the hole have the same charge but the polarity is opposite , the combination will lead to a neutral compound , i.e. , Exciton have no charge and so neutral .
It is free to move in the nonmetallic crystal and since it charge less , it is difficult to detect it directly .
