7.3

1) Atomic radius of elements is a measure by the size of its atoms typical distance from the nucleus to the boundary of the surrounding cloud of  electrons. Because heavier elements have more particles in the nucleus (number of protons and number of neutrons), the nucleus would have a stronger attractions to the electrons, which would cause the radii to be smaller.

2) Electronegativity is a measure of the ability an atom has to attract electrons to it in a bonding situation. the larger the element, the less electronegativity the element has because the electrons are further away from the nucleus, and the harder it is for these elements to bond.

3) Ionization energy is a measure of the amount of energy needed in order to rip the most loosely held valence electron away from an atom.The non-metals are harder to strip an electron away than metals because non-metals want to gain electrons, whereas metals want to loose their electrons. Also generally top right non-metals have greater number of protons and electrons in their nucleus, so they hold a better attraction to their electrons.

4)Trends are referred to being periodic because periodic means how something goes in an order/pattern and happens in certain intervals, like the Periodic Table.

Lab 7.2

Using pennies as isotopes in our lab we didn't come across any problems. If the atomic mass of flourine is 18.99, this is because it's isotope Cl-19 is more abundant than Cl-17. These two isotopes share the same protons but a different number of neutrons.
       A mass spectrometer sperates and detects ions of slightly different masses, easily sperating different isotopes of an element. After the ions are seperated and measured they are displayed on a graph
      Inside a U-238 atom there are 92 protons and 146 neutrons. When the nucleus catches a moving neutron it splits into two(fissions) and when this happens energy is released in heat from, also throwing some neutrons. If enough of these are thrown off it can cause another atoms nuclei to split, creating a chain reaction. When this happens over and over again very large amounts of heat can be produced from amounts of uranium. In nuclear power plants machines can be run off of this process. 

Blog 7.1

I think that an elements spectrum is called it's fingerprint because like a fingerprint every spectrum is atleast slightly different and it is its own special thing. This helps us to determine which element is which, because none of them are identical. When atoms leave their ground state and enter their "excited state" they return back to their original ground state. When this happens light is omitted and depending on the elements electrons different colors.

     When an element is changing from it's ground state to an excited state the electrons absorb energy and move to higher energy levels. 

     Helium was originally discovered in the sun, before on earth.

     A red shift happens when light seen coming from an objects are increased in wavelengths, or shifted to the red side of the spectrum. A blue shift happens when there is a decrease in the wavelength and it becomes shifted towards the blue side of the spectum. Because of the increasing wavelengths in red shifts the distances of the objects are becoming larger and this is creating the universe to expand.