Lab 7.3 Reactivity Of Metals

1. Elements in the same group rather than the same period have the most similar proprieties, because for the most part, atoms in the same group have the same number of valence electrons. This means that they will react in the same way, making the same bonds to other atoms.

2. Elements in the same group on the Periodic Table tend to react the same way because they have the same number of valence electrons. For example, Magnesium would react similarly to Beryllium because they are both in group 2 (Alkali Earth Metals), and each have 2 valence electrons.

3. With an electron configuration of 2-8-1, when Sodium reacts with a nonmetal, it loses its valence electron, making it a cation, with a charge of +1. Also the Sodium ion will have a new electron configuration of 2-8, making it most similar to the noble gas Neon (Ne). As a result of this, the Sodium ion has become more stable.

Enrichment: Pure Sodium is created through a Carbon Burning Process(also caller Carbon Fusion). This is when two Carbon atoms are fused together at an extremely hot temperature, creating what we used in the lab, Na-23.

Chem Crunch Blog

The heaviest elements have the smallest radii because they are the most dense, due to the mass packed into a smaller atom.

Electronegativity decreases as the groups decrease because nonmetals are the most electronegative. Elements in higher groups have the most nonmetalic properties. Also, when an atom is larger, the valence electrons are farther away from the positive nucleus, which is why the larger atoms don't attract electrons as well.

The trends are referred to as being periodic, because they happen periodicly, just as magazines and newspapers come periodically (often).

Lab 7.1 Flame Tests And Emission Spectra

Conclusion:
1.) A spectrum is like an element's fingerprint, because each element releases a different emission spectrum. Since elements have different elecrtron configurations, when an atom of an element goes from the excited state back to the ground state, its light emission spectrum will be different from any other. Just as fingerprints are used for identification purposes, as can an emission spectrum. Since all light spectra are different, depending on the element, a spectrum can be used to determine which element is releasing it.
2.) A spectrum is formed when an atom is going from the excited, back into the ground state. This is because the energy that was once absorbed, now needs to be released, in the form of light energy. This process is happening so rapidly, that when we see light, it appears to be a constant, when really it is this individual process happening to millions of atoms, happening millions of times.

Enrichment:
1.) Jules Janssen was the man that discovered Helium. He gave the element the name Heliom after the Greek God, Helius, because he discovered it during a solar eclipse.
2a.) Blue and red shifts are the shifts of wavelengths toward one side of the color spectrum, thus making it appear more red or more blue, and also making the wavelength shorter or longer, depending on which shift has occurred.
2b.) Red shift galaxies are much more abundant than blue shift galaxies. Since a blueshift is a decrease in wavelength (an increase in frequency), it will increase the velocity of particles. This increase in particles creates the doppler effect, because as the universe is expanding, the frequency will appear to increase even more. Theoretically, the two are directly connected.
2c.) Edwin Hubble was an American astronomer, for whom the Hubble Telescope was named. His advances in theoretical Physics, and astronomy helped create a better understanding for many theorys relatesd to redshift, blueshift, and the expanding universe.