Temperature means, in this context, movement.
Condensation can be explained by the reduction of temperature of the system. This effect make possible the cohesion forces increases. In other words, the result is coalescence by attractive forces.
Answer:
d. Cl2
sorry if I'm wrong
Cl2, as shown in the picture should have electrons in both the atoms but, in the question, the electrons are only in one of the atoms.
hope it helps :)
Answer:
The energy difference between these 2p and 2s orbitals is 
Explanation:
Wavelength of the photon emitted = 
Energy of the photon will corresponds to the energy difference between 2p and 2s orbital = E
Energy of the photon is given by Planck's equation:

h = Planck's constant = 
c = Speed of the light = 


The energy difference between these 2p and 2s orbitals is 
3 elements are present in HCOOH - hydrogen, oxygen, and carbon.