Answer:
8239.2g
Explanation:
Given parameters:
Number of atoms in Br = 6.2 x 10²⁵atoms
Unknown:
Mass of Br = ?
Solution:
From mole concepts, we know that:
1 mole of a substance contains 6.02 x 10²³ atoms/mol
Molar mass of Br = 80g/mol
6.2 x 10²⁵atoms x
x 80 x
= 8239.2g
Answer : The time passed in years is
Explanation :
Half-life of carbon-14 = 5730 years
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the time passed.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant =
t = time passed by the sample = ?
a = initial amount of the reactant disintegrate = 15.3
a - x = amount left after decay process = 14.8
Now put all the given values in above equation, we get
Therefore, the time passed in years is
