Lab 7.4: Reactivity of metals

1 and 2. Elements that are in the same group have more similarities than elements in the same period. Elements with the same number of valence electrons and similar properties are most similar. These similar elements share the same characteristics and reaction times.This can be proved from the data we collected when metals were being place into water and phenolphthalein.When the data was collected the six elements could be easily placed in three different groups based on properties observed.Group 1 (Na, K, and Li), properties for this group were started with each containing one valence electron then observing that the element reacted fast with the air, the elements floated in water, an exothermic reaction,and the water (phenolphthalein turned pink) meaning that the element is basic. Knowing these similarity's it can be concluded that all of these elements are in Group 1.The elements in our group 2 (Mg and Ca) also shared many identical properties and both had valance electrons of 2. And finally, the group left had only contained the element Al. Al had different properties than all the other elements, also had a different valance electron valance electron of 3.

 

3.When an element of sodium reacts with an non-metal:

a) the sodium atom will want to lose1 electron(metals loses electron) so that it can get to a stable octet.

b) the sodium ion will become positive ion called a cation. This is caused by loosing an electron there is one more proton, making it positive.

c) 1+

d) Its new electron configuration would be 2-8 that of Neon

e) The sodium ion will be more stable because it has 8 valance electrons resulting in a stable octet. 

Enrichment:

Alkali metals almost always form ions with a positive charge of +1, and are so reactive as elements that virtually all occur in nature only in compound form. Sodium a highly reactive element is in its pure form reacts with elements and moisture in the air almost immediately. It is more stable in compounds, so this is how it is found in nature.Pure sodium metal can be prepared by the process involves the electrolysis of NaCl mixed with proper amount of CaCl₂ to lower the melting point of NaCl. this process produces up to 99% pure sodium metal

7-2 Atomic mass of Pennium.

Pennies were good as isotopes because depending on the generation pre or post 1982 the penny contains a different ratio of zinc and copper.The new generation penny with less copper can be considered an isotope of pre 1982 penny's almost made of pure copper. A problem that can occur using penny's as an isotope is that they don't have a constant (like atomic number) like real elements and their isotopes.
1.The atomic mass is 35.45 amu. You multiply the mass number by the abundance percentage and add them with the abundance of the other isotope times its mass. Since the atomic mass is closer to Cl-35 it shows that it is more abundant then Cl-37.
2.Cl-35 and Cl-37 both share the same number of protons and neutrons within the nucleus. The isotope of Cl-35 is Cl-37 this happens when there are more neutrons in the nucleus added to the atomic mass.
3. Mass number and atomic mass differ in that atomic mass is the mass of one element, simply the elements wieght. The mass number isthe added wieght of another individual element. For example CuCl2 (copper chloride) mass is the added mass of Cu's atomic mass times how many Cu atoms you may have plus that of Cl because of the ionic bond you have to elements to add.
Enrichment:
1. A spectrometer is an instrument used to measure  characteristics of individual molecules. A mass spectrometer converts them to ions so they can be moved  and manipulated by electric and magnetic fields.
2. Natural uranium is only 0.7% uranium-235, a type of uranium that undergoes fission in this type of reactor.The reactor uses Uranium as fuel, and  heat is generated by nuclear fission (neutrons smash into the nucleus of the uranium atoms) split roughly the uranium atom in half and release energy in the form of heat the rest is U-238.Modern reactors use "enriched" uranium fuel, which has a higher proportion of U-235.

7-3 Periodic trends Activity

• Atomic radii trend decreases as you move from left to right. This is because the left of the table contains metals with a weak attraction for electrons. Meaning the electrons radius is farther away from the nucleus this is what makes it easier for metals to loose electrons.The heavist elements in a period have the smallest radii because the electrons are more attracted and closer to a larger mass pulling the electron shells closer.
• Elements at the bottom  of a group have the lowest electronegativity because it is the most metallic having the smallest ionization energy Making it easiest for the element to loose electrons.
• The non-metals are harder to take an electron away than metals because non-metals want to gain electrons, whereas metals want to loose their electrons.
• Trends are referred to as periodic because it represents a pattern that happens in the elements throughout a certain period hence the "periodic table".

Lab 7.1: Flame Test and Emission Spectra

The spectrum of light is often refered to as the "fingerprint" of an element. As each element moves through the ground state to the excited state the electrons absorb energy and jump to a higher level. This is shown in the electron configuration where the electrons seem out of order and moved into a new orbital as the electrons move higher up with more energy. As the excited element goes back to the ground state electrons go back to the original configuration emitting/releasing extra energy in the form of light called spectra. Each element had there own bright line spectrum making them unique from one another like fingerprints.

Enrichement:

1.The astronomer Pierre Janssen discovered helium after studying the Sun during a solar eclipse.The spectral lines, he discovered was not any known element. He said that there must be an element on the Sun that had never been seen on Earth. The name comes from the Greek word helios for "sun."

2. A blue shift is when the spectra wavelength signals are shortened meaning the object is getting closer and the light emitted is on the blue end of the spectrum. The opposite effect called res shift is a longer wave length emitting light on the red end of the spectrum telling you something is moving farther away from the observer. The red shift and blue shift are evidence that the universe is expanding because all the galaxies in the universe are red shifted. Hubble approximated the relationship between redshifts and the distance with the formulation of Hubbles law.