Answer : The energy of the photon emitted is, -12.1 eV
Explanation :
First we have to calculate the
orbit of hydrogen atom.
Formula used :

where,
= energy of
orbit
n = number of orbit
Z = atomic number of hydrogen atom = 1
Energy of n = 1 in an hydrogen atom:

Energy of n = 2 in an hydrogen atom:

Energy change transition from n = 1 to n = 3 occurs.
Let energy change be E.

The negative sign indicates that energy of the photon emitted.
Thus, the energy of the photon emitted is, -12.1 eV
B. inference because she drew a conclusion based on evidence.
Because the evidence was that she heard the crashing sound, and then when she came into her room saw the broken window and baseball.
It was not an observation because she did not directly see the baseball going through the window
2K + Cl₂ ⇒ 2KCl
2Ca + O₂ ⇒ 2CaO
Answer:
metal atom
Explanation:
metallic solid has layers makes it soft and it also has electron that can carry charge and conduct electricity.
1.3*10^1 would be the answer