Respuesta :
Answer:
7.4eV
Explanation:
We are given tha
Energy of a particular atom in a gas in the first excited state=5.2 eV
Kinetic energy of the electron after collision=K.E=2.2 eV
We have to find the kinetic energy of the electron just before the collision.
We know that energy transferred from one particle to other atom.
By conservation law of energy
Kinetic energy of electron just before the collision=K.E of electron after collision+ energy of atom in a gas in the first excited state
Kinetic energy of electron just before the collision=2.2e V+5.2 eV=7.4eV
Hence, the kinetic energy of electron just before the collision=7.4 eV
The initial kinetic energy of the electron is 7.4 eV.
The ground state is the lowest energy state of the atom. Other higher energy states are called excited states. An atom can receive energy and move from ground state to excited state.
In this case; Kinetic energy lost by the electron = energy used to excite the atom = 5.2 eV
Kinetic energy of the electrons after collision = 2.2 eV
Hence, kinetic energy of the electron before collision = 5.2 eV + 2.2 eV = 7.4 eV
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