What must be done to an atom before it can emit light?

Raise the electrons to a higher energy level by exposing to radiation; light, elelectromagnetic,heat etc etc.

Does an atom need to be ionised before it can emit light?

Any free electron will give off a photon as it gets bound to the ionized atom. Now, strictly speaking, ionization is not necessary for fluorescence to occur. An external force such as an electric current might simply provide enough energy for a low-orbital electron to “jump” to a much higher-orbital.

Does light go through atoms?

When light falls on a material, the energy in its photons can affect the atoms in the material. In some materials, such as metal, the atoms absorb some of the photons so light does not pass through them. In other materials, such as glass, the atoms cannot absorb the photons and light passes through them.

What must happen within an atom for a blue photon to be emitted?

It has to be excited. One of its electrons has to be in a higher energy level from which it can fall back into a lower state. In doing so it will emit a photon.

How is light emitted from an atom *?

An atom can absorb or emit one photon when an electron makes a transition from one stationary state, or energy level, to another. Conservation of energy determines the energy of the photon and thus the frequency of the emitted or absorbed light.

How are photons emitted from an atom?

When the electron changes levels, it decreases energy and the atom emits photons. The photon is emitted with the electron moving from a higher energy level to a lower energy level. The energy of the photon is the exact energy that is lost by the electron moving to its lower energy level.

When an atom is ionised what does it become?

An atom becomes ionised when it becomes charged. Electrons are negatively charged. So if an atom GAINS an electron it becomes more negatively charged. Oppositely if an atom LOOSES an electron it looses that negative charge so itself becomes more positive ie more positively charged.

What does it mean when something is ionised?

ionization
ionization, in chemistry and physics, any process by which electrically neutral atoms or molecules are converted to electrically charged atoms or molecules (ions). Ionization is one of the principal ways that radiation, such as charged particles and X rays, transfers its energy to matter.

What happens when an atom emits light?

What must happen within an atom for a blue photon to be emitted versus a yellow photon?

If a blue photon hits and electron the electron will be ejected since a blue photon has more energy than a yellow photon. Since a blue photon has more energy than a yellow photon, the extra energy goes into increasing the kinetic energy of the electron.