If you like us, please share us on social media.
The latest UCD Hyperlibrary newsletter is now complete, check it out.
Copyright (c) 2006-2014 MindTouch Inc.
This file and accompanying files are licensed under the MindTouch Master Subscription Agreement (MSA).
At any time, you shall not, directly or indirectly: (i) sublicense, resell, rent, lease, distribute, market, commercialize or otherwise transfer rights or usage to: (a) the Software, (b) any modified version or derivative work of the Software created by you or for you, or (c) MindTouch Open Source (which includes all non-supported versions of MindTouch-developed software), for any purpose including timesharing or service bureau purposes; (ii) remove or alter any copyright, trademark or proprietary notice in the Software; (iii) transfer, use or export the Software in violation of any applicable laws or regulations of any government or governmental agency; (iv) use or run on any of your hardware, or have deployed for use, any production version of MindTouch Open Source; (v) use any of the Support Services, Error corrections, Updates or Upgrades, for the MindTouch Open Source software or for any Server for which Support Services are not then purchased as provided hereunder; or (vi) reverse engineer, decompile or modify any encrypted or encoded portion of the Software.
A complete copy of the MSA is available at http://www.mindtouch.com/msa
Every atom is different in its number of protons, its mass, and its size. The size of the atoms is determined by the size of their orbitals. The larger the quantum number "n" is, the larger the orbital is, which increases the size of the atom.
Each atom has different number of orbitals. These orbitals differ in size depending on where they are on the periodic table. The size of the orbitals determines the atomic radius for each atom. As you go down a group, the quantum number "n" increases meaning that the size of the orbital and the atomic radius increases as well.
Every atom has four quantum numbers, but the only one that matters in the size of the atom is the quantum number "n". As "n" increases, so does the size of the orbital. As "n" decreaes, the size of the orbital decreases as well.
The size of the orbital determines the radius of an atom. As you go down a group on the periodic table, the size of the orbital increases meaning the atomic radius increases as well. The increase of size in the orbital is due to the increase of the quantum number "n".
The size of the orbital and the atomic radii decreases as you go across a period from left to right. This is due to the fact that as you go from left to right across a period, the number of protons increase as well as the number of electrons. The more electrons there are, the closer they are to the nucleus due to the stronger interactions between them, which decreases the size of the orbital and the atomic radius.
Figure 1. General Trend of how the radius change within the Periodic Table
The atomic radii of cations and anions follow a different trend compared to the neutral atoms. Cations have less electrons than their neutral atoms. Since there are less electrons, they are more attracted to the increased positvie charge at the nucleus. The electrons pack themselves closely to the nucleus, which leads to a decrease in the atomic radius.
Anions have more electrons than their neutral atoms. Because there are more electrons, repulsion within that ion is high. The repulsion between electrons cause the electrons to spread out as far away from each other as possible. The spreading of the electrons within the orbital increases the atomic radius.
Lanthanide contraction decreases the atomic radii starting from the lanthanide series. The decrease in atomic radii is due to the poor shielding of the 4f electrons.
1.) What does the size of the orbital depend on?
2.) Which one is bigger?
a.) Li b.) K c.) Rb d.) Fr
3.) Which one is bigger and why?
a.) Ca b.) Ni c.) Zn d.) Cr
1.) Going down a group, it depends on how large "n" is. Going across a period, it depends on how closely the electrons are attracted to the nucleus.
2.) d.) Fr--simply follow the periodic trend as stated in Problem 1.
3.) a.) Ca because compared to the others, it has the least amount of electrons meaning that they aren't packed closely to the nucleus increasing its size.
An NSF funded Project