When an atomic nucleus emits an alpha particle it decay into an atom with atomic number 2 less and mass number 4 less. Thus Thorium 230 decay as follows.
230 90Th -------> 226 88Th + 4 2 He
thorium is in the atomic number 90 thus it during alpha decay it reduces to atomic number 88 while its 230 mass number reduces to 226
Answer: 
molecules of water are produced.
Explanation:
To calculate the moles :
The balanced chemical reaction is:
According to stoichiometry :
2 moles of 
produce = 3 moles of 
Thus 0.707 moles of will produce=
of
According to avogadro's law, 1 mole of every substance contains avogadro's number 
of particles.
Thus 1.06 moles of contains = 
molecules
The answer is Al.
If it is a main group element with 3 electrons in its Lewis dot structure, it must be in group 3A. If it is in the 3p orbital section, then it must be in period 3, since the p orbital is a valence orbital and the number that preceeds it is the principal quantum number. Therefore, your answer is the element in period 3 and group 3A, which is aluminum.
Answer:
Initially 
of nitrogen dioxide were in the container .
Explanation:
Volume of the container at low pressure and at room temperature =
Number of moles in the container = 
After more addition of nitrogen gas at the same pressure and temperature.
Volume of the container after addition = 
Number of moles in the container after addition=
Applying Avogadro's law:
(at constant pressure and temperature)
Initially of nitrogen dioxide were in the container .
