Answer:

Explanation:
1. Calculate the rate constant
The integrated rate law for first order decay is

where
A₀ and A_t are the amounts at t = 0 and t
k is the rate constant

2. Calculate the half-life

Answer:
90.
Explanation: yea and I will be back at your
Answer:

Step-by-step explanation:

Data:
n = 5 mol
V = 2.5 L
Calculation:

The molar concentration of the solution is
.
Answer: Option (D) is the correct answer.
Explanation:
Valence shell is the shell present on the outermost core of an atom and electrons present in the valence shell are known as valence electrons.
If an atom has completely filled valence shell then it means the atom is not reactive in nature because it is already stable.
But when an atom has less than eight electrons in its valence shell then it means to attain stability the atom will readily attract electrons towards itself.
As the given element 1 has 8 electrons in its valence shell. Hence, it is not reactive in nature but element 2 has 6 valence electrons. So, in order to attain stability element 2 will readily attract 2 electrons from a donor atom.
Thus, we can conclude that element 2 is more reactive because it does not have a full valence shell, so it will attract electrons.