Normal Matter

The matter inside a neutron star is nothing like matter here on Earth. It is called degenerate matter, specifically neutron degenerate matter. There are different types of degenerate matter. We will explore how the matter in a neutron star becomes degenerate.

Let’s check out normal matter first:

Observe the balloon on the table. Use the circle below to represent the balloon.

  1. Specifically, what is inside the balloon? (I know air, but describe what is meant by air)
  2. What keeps the balloon from exploding open?
  3. What keeps the balloon from imploding?
  4. Draw the forces acting to keep the balloon inflated.
  5. What will happen if we heat the air inside the balloon?

Let’s review what we have learned about matter from Chemistry. List the 4 states of matter and describe their motions and energies.

State of Matter / Describe the motion of the particles / Rank in order of increasing energy / Describe density if constant volume
1. 
2. 
3. 
4. 

If you add enough thermal energy to a substance such as water it will change its physical state. You can also change the state of a substance by changing pressure.

Questions:

  1. What happens to “normal matter” when it is heated?
  2. Describe the conditions in which water cannot exist as a liquid.
  3. What happens to carbon when it is under extreme pressure (at any temperature)?

In a hydrogen atom, the electron has lots of room to move. It can exist in 1 of several energy levels and in a variety of orbitals and with an up or down spin. So the electron, while confined to these energy levels, orbitals and spins, have lots places in the atom they can life. The atom is mostly free space.

Below is a diagram that shows the energy levels of the hydrogen atom. The diagram shows many of the transitions the electron can make in those energy levels.


If the right amount of energy is added to the atom the atom can be ionized. Ionization is the process of converting an atom or molecule into an ion by adding or removing charged particles such as electrons or ions. In the case of ionization of a gas, ion pairs are created consisting of a free electron and a positive ion. The loss of electrons, which is the more common process in astrophysical environments, converts an atom into a positively charged ion, while the gain of electrons converts an atom into a negatively charged ion. We will use the terms ionization and ionize in the sense of losing electrons to form positive ions. If most of the atoms or molecules in a region are ionized, the resulting state of matter corresponds to a gas that is electrically neutral on a global scale, but composed microscopically of positively charged ions and the negatively charged electrons stripped from the atoms to form the ions. Such a state of matter is called a plasma. Most of the matter in stars is in a plasma state. Thus, although what we refer to as "normal matter" consists of atoms and molecules, the evidence is that the most abundant form of matter in the Universe is not atoms and molecules but rather the plasma state.

Questions:

  1. Draw, label and describe a hydrogen atom.
  2. Describe how an electron can move around in an atom. Where can it be and where can it not be?
  3. What is an ion?
  4. Describe the process and end products when a hydrogen atom is ionized. What is this state of matter called?
  5. What is the most abundant form of observable matter in the universe?

Pulsar AstronomyPage 4