Answer:
it's lead (ii) nitrate the name
Rounded to 1 significant figure, 25 m would go to 30. This is because 0 isn't significant, so the 3 is the only significant figure.
When alpha decay takes place, two protons and two neutrons are forcefully ejected from the nucleus in a way that looks very similar to a Helium nucleus. This type of decay causes the atomic mass of the parent particle to drop by four (four particles lost), but the atomic number drops by only two (two protons lost). Therefore, your answer is C.
Answer: It will take 8.2 minutes until the concentration decreases to 0.055 M
Explanation:
The time after which 99.9% reactions gets completed is 40 minutes
Explanation:
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.


b) Time taken for 0.085 M to decrease to 0.055 M


Thus it will take 8.2 minutes until the concentration decreases to 0.055 M