Rachel

Book Definitions
 * Trends on the Periodic Table**
 * Ionization Energy- the amount of energy an atom must receive in order to remove an electron.
 * Atomic Radius – ½ the distance between the centers of two like atoms.
 * Shielding Effect – a reduction in the attraction of the outer electrons to the positively charged nucleus.
 * Electronegativity – (EN) – the attraction of an atom, when it’s found in a compound, for the electrons in the other atom of the compound.
 * Electron Affinity – measure of the energy change as an electron is added to an atom.

Ionization Energy: energy used to the remove an electron 8=======D-o
 * Increases horizontally
 * decreases vertically
 * The closer the electron is to the nucleus, the higher the ionization energy (larger attraction = harder to remove the electron)

Atomic Radius: 8====Do Shielding Effect: 8====D123327126412332712641233271264user:rlsmithrachelö
 * decreases horizontally because there are more protons and electrons (larger attraction = smaller radius)
 * increases vertically (there are more energy levels = larger radius)
 * Horizontally - the shielding effect is constant (electrons stay in the same energy level)
 * Vertically - the shield gets bigger and blocks more electrons

Electronegativity: the measure of the tendency of an atom to attract a bonding pair of electrons. 8====D123327126412332712641233271264user:rlsmithrachelö
 * Horizontally – bigger (more control over electrons)
 * Vertically – smaller (less control over electrons)
 * top right = most electronegative (excluding the noble gases)
 * bottom left is the least electronegative.

Electron Affinity: measure of energy change 8=====D--o
 * Horizontally - more negative
 * Vertically - More positive

covalent bond: chemical bond that forms when atoms share their electrons (www.chemguide.co.uk/atoms/bonding/electroneg.html ) electronegativity: the ability of the atom to attract electrons towards itself in a covalent bond (www.chemguide.co.uk/atoms/bonding/electroneg.html ) pic of covalent bond pic of lewis dot structure **Naming Covalent Bonds** Example: BF 3 - Boron trifluoride N 2 O 5 - Dinitrogen pentaoxide ** Drawing Lewis Dot Structures ** Exceptions to Octet Rule
 * 1) elements are listed by lower group first
 * 2) if both elements are in the same group, the lower atomic number element is the first of the bond
 * 3) 2nd element will end with -ide
 * 4) prefixes are used to tell how many atoms are in the bond (mono, bi, tri, etc)
 * 5) first element will only have a prefix if it is more than one
 * Covalent Bonds- one or more bonds made between elements when the bond is mae by the sharing of electrons
 * Single Bonds- sharing of 2 electrons between 2 elements
 * Double Bonds- sharing of 4 electrons between 2 elements
 * Triple Bonds- sharing of 6 electrons between 2 elements
 * 1) draw the Lewis Dot structure for each element
 * 2) place the element having the most unpaired electrons in the center
 * 3) bond as many single elements to the center element as possible - keep balance as you draw
 * 4) create double/triple bonds as necessary to reach the octet for all elements
 * Drawing Ions (with a charge) **
 * Carbonate (CO 3 )- ²
 * the -2 means that you will have to add two extra electrons to have all elements reach the octet rule
 * elements with 3,5,7 valence electrons
 * can be stable without meeting the Octet rule
 * 3 w/ 6 electrons bonding
 * 5 w/ 10 electrons bonding
 * 7 w/ 14 electrons bonding