1. Elements that are in the same group have more similarities in their properties than those in the same period. For example, Potassium and Lithium both reacted with air and produced gas in water.
2. Elements are very similar in the same group because they have the same number of valence electrons, and all want to lose/gain the same number of electrons.
3. When a sodium atom reacts with a non metal, sodium loses one electron and gets a charge of +1. This now makes it a positive ion. The electron configuration of sodium after reacting is the same as the noble gas neon. Sodium becomes more stable after reacting because it doesn't want to lose or gain anymore electrons, and has a full valence electron shell.
Wednesday, February 15, 2012
Monday, February 13, 2012
Lab 7.2 Periodic Trends Activity
Heavier atoms have more protons and electrons. The protons and electrons are attracted to eachother, so more protons and neutrons means more attraction within an atom. This will make the atom more closely packed together, making the radii smaller.
If an atom is larger, it means there are more electrons in the way of the proton. This decreases the positive attraction, making it harder to attract electrons and decreasing electronegativity.
It is harder to take electrons from non metals as opposed to metals because non metals want to gain electrons, as metals want to lose them.
Nuclear charge is the positive charge an electron has in an atom.
Its called the Periodic Table because there are trends that occur periodically.
If an atom is larger, it means there are more electrons in the way of the proton. This decreases the positive attraction, making it harder to attract electrons and decreasing electronegativity.
It is harder to take electrons from non metals as opposed to metals because non metals want to gain electrons, as metals want to lose them.
Nuclear charge is the positive charge an electron has in an atom.
Its called the Periodic Table because there are trends that occur periodically.
Wednesday, February 8, 2012
Blog 7.1 Flame Tests and Emission Spectra
The spectra of an element is called its fingerprint because they're all different. More specifically, it's their electron configuration when coming out of the excited state into the ground state.
Once a certain amount of energy is absorbed by an element, an electron can jump up a shell. This is called the excited state. It's very unstable in this state and can't stay this way for very long. When it goes back to the ground state, energy is released in the form of light. This pattern of light released is unique to each element and is called a spectra.
Example: 2-8-8 (ground state) 2-8-7-1 (excited state)
Enrichment: Helium was named after Helios, the Greek sun god. A redshift is when light seen is shifted to the red end of the spectrum. Sir Edwin Hubble created Hubbles law, which states all objects observed in space are found to have a wave length shift that correlates with earth.
Once a certain amount of energy is absorbed by an element, an electron can jump up a shell. This is called the excited state. It's very unstable in this state and can't stay this way for very long. When it goes back to the ground state, energy is released in the form of light. This pattern of light released is unique to each element and is called a spectra.
Example: 2-8-8 (ground state) 2-8-7-1 (excited state)
Enrichment: Helium was named after Helios, the Greek sun god. A redshift is when light seen is shifted to the red end of the spectrum. Sir Edwin Hubble created Hubbles law, which states all objects observed in space are found to have a wave length shift that correlates with earth.
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