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:
32.6 %
Explanation:
Given data
- Mass of sucrose (solute): 22.8 grams
- Mass of water (solvent): 47.1 grams
Step 1: Calculate the mass of the solution
The mass of the solution is equal to the sum of the mass of the solute and the mass of the solvent.
m(solution) = m(solute) + m(solvent)
m(solution) = 22.8 g + 47.1 g
m(solution) = 69.9 g
Step 2: Calculate the percent-by-mass of sucrose in the solution
We will use the following expression.
Answer:
850 Calories.
Explanation:
The following data were obtained from the question:
Mass (M) = 50 g
Initial temperature (T1) = 20 °C
Final temperature (T2) = 37 °C
Specific heat capacity (C) of water = 1 cal/g°C
Heat absorbed (Q) =..?
Next, we shall determine the change in temperature of water.
This can be obtained as follow:
Initial temperature (T1) = 20 °C
Final temperature (T2) = 37 °C
Change in temperature (ΔT) =..?
Change in temperature (ΔT) = T2 – T1
Change in temperature (ΔT) = 37 – 20
Change in temperature (ΔT) = 17 °C
Finally, we shall determine the heat absorbed. This can be obtained as follow:
Mass (M) = 50 g
Specific heat capacity (C) of water = 1 cal/g°C.
Change in temperature (ΔT) = 17 °C
Heat absorbed (Q) =..?
Q = MCΔT
Q = 50 x 1 x 17
Q = 850 Calories
Therefore, the heat absorbed is 850 Calories.
