Answer : The final concentration of 
is, 2.9 M
Explanation :
Expression for rate law for first order kinetics is given by:
where,
k = rate constant = 
t = time passed by the sample = 3.5 min
a = initial concentration of the reactant = 3.0 M
a - x = concentration left after decay process = ?
Now put all the given values in above equation, we get
Thus, the final concentration of is, 2.9 M
Answer:
with the proton inside the nucleus
A
single oxygen has atomic number 8 that means the nuclei of all oxygen atoms
have eight protons. The number of minus-charged electron is two but the number
of electrons is 10. <span>To gain a minus two-charge ion, it
must have two more negative electrons than positive charged protons. With this,
the ion has 10 electrons, which give it a -2 net charge. </span>
