It has to be D. the time needed to boil the water decreased
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.
A substance which allows energy (heat or electricity) to pass through it is known as a conductor.
These substances usually have free electrons which allows the charges to flow easily in the substance, thus, transferring energy.
Other substances which do not have free electrons and do not allow energy to pass through them are known as insulators.
Density is found by dividing mass over volume:
d=M/V. In this problem, we know the density, and the mass. Solve the general equation for volume, then enter the values from the problem and evaluate:
d=m/v [multiply v to both sides, then divide d from both sides]
v=m/d
v=83.8g/(2.33g/cm³)
v=35.965 cm³
v=36.0 cm³ to three significant figures (since your given information only has 3 sig figs)
