The half-life of Palladium-100 is 4 days. After 12 days a sample of Palladium-100 has been reduced to a mass of 4 mg. What was the initial mass (in mg) of the sample?

Answer : The initial mass of the sample is, 31.9 mg

Explanation :

Half-life = 4 days

First we have to calculate the rate constant, we use the formula :

Now we have to calculate the initial mass of sample.

Expression for rate law for first order kinetics is given by:

where,

k = rate constant  =

t = time passed by the sample  = 12 days

a = initial amount of the reactant  = ?

a - x = amount left after decay process = 4 mg

Now put all the given values in above equation, we get

Therefore, the initial mass of the sample is, 31.9 mg

hope this

explanation:

covalent bonds

consist of pairs of electrons shared by two atoms, and bind the atoms to fixed orientation and requre high energies to break them

ionic bonds

when two atoms differ considerably in their electronegativity, then one of the atoms will lose its electron to the other atom. this results in a positively charged ion(cation) and a negatively charged ion (anion)

c, liquids evaporate, creating a gas