Answer:
<em>What can be added to an atom to cause a nonvalence electron in the atom to temporarily become a valence electron </em>is<u><em> energy</em></u><em>.</em>
Explanation:
The normal state of the atoms, where all the electrons are occupying the lowest possible energy level, is called ground state.
The <em>valence electrons</em> are the electrons that occupy the outermost shell, this is the electrons in the highest main energy level (principal quantum number) of the atom.
So, a <em>nonvalence electron</em> occupies an orbital with less energy than what a valence electron does; in consequence, in order to a nonvalence electron jump from its lower energy level to the higher energy level of a valence electron, the former has to absorb (gain) energy.
This new state is called excited state and is temporary: the electron promoted to the higher energy level will emit the excess energy, in the form of light (photons), to come back to the lower energy level and so the atom return to the ground state.
Answer: The rate constant is
Explanation ;
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = ?
t = age of sample = 4.26 min
a = initial amount of the reactant = 2.56 mg
a - x = amount left after decay process = 2.50 mg
Now put all the given values in above equation to calculate the rate constant ,we get



Thus rate constant is [tex]0.334s^{-1}
Answer:
where is the option I can't see plz give the option first the I try to give answer
It is necessary to make a logical system for naming compounds because there are so many of them and thinking of arbitrary random names for each one and then later remembering them all would be impossible. Also, they need to be all recognized and standardized for global use so as to have everyone use the same system.