Solar Energy Introduction Course

Theory

Exercises

Lection 0: Electric Charge

Exercises

Solution: The new charge of the Helium atom without its two electrons would be +2. This is because this Helium atom now only has two neutrons, which have no charge and two protons which have one positive charge each. This sums up to a total charge of +2.

This picture presents a Helium atom. The yellow little balls with the minus sign in them are the two electrons. The red larger balls with the plus sign in them are the protons and the green balls are the neutrons. Note how the number of electrons is exactly the same as the number of protons.
Most of the Helium atoms have two neutrons.

Now as an exercise imagine a Helium atom. A neutral Helium atom has two neutrons, two protons and two electrons. See the picture on the left for the example of a Helium atom.
As it is neutral, its charge is zero.

Now imagine if this Helium atom looses all of its electrons. What would the charge of this new Helium atom be?

Think about the solution and hover the mouse pointer over the picture to see the solution to see if you were correct.

Solution: The new charge of the Hydrogen with the additional three atoms would be -3. This is because this atom has now tree more electrons than it has protons.

This picture presents the Hydrogen Atom. It is the smallest atom with only one proton, one neutron and one electron.

As a second exercise imagin the Hydrogen atom. See how many neutrons, protons and electrons the neutral Hydrogen has. If now two free electrons came along and would attache themselfes to this Hydrogen atom, what would the charge of this new Hydrogen atom be?

Think about the solution and hover the mouse pointer over the picture to see the solution and check if you were correct.

Solution: The periodic number indicates the number of protons an atom has.

This is a Copper atom. It belongs to the family of metal atoms. Copper is one of the best conducter of current, that is in usage. Note that the number of neutrons is not the same as the number of protons. Acctually, in most of the atoms, the number of protons is not the same as the number of neutrons.

As a last exercise, search the copper atom on the periodic table. See the number next to the name, this is the periodic number. What could this number mean? Compare the periodoc numbers of the other atoms depicted here, to verify your thoughts.

Think about the solution and hover the mouse pointer over the picture to see the solution and check if you were correct.

Electric Circuitsin Solar Installations

Lection 0: Electric Charge

Exercises

Electric Circuits
in Solar Installations