LEWIS & VSEPR - Remember the first step to visualize a...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Remember the first step to visualize a molecule is to convert its molecular formula to its Lewis structure or Lewis formula. In many cases, the octet rule guides us in allotting the electrons to the atoms, in other cases we set the rule aside. Lewis structures : Step 1 - Place the atoms relative to each other – Generally, the element with lower group number is in the center because it needs more electrons to attain an octet. If the elements are in the same group, the element of the higher period is in the center. In addition, as a reminder H never goes in the center because can form only one bond. Step 2 – Determine the total number of valence electrons available – recall # of valence electrons equals the A-group number. Remember in case of polyatomic ions you add one e- for each negative charge and subtract one e- for each positive charge. Lewis structure of polyatomic ions is shown in square brackets, with its charge as a right superscript outside the brackets. Step 3 Draw a single bond from each surrounding atom to the central atom, and subtract two valence e- for each bond and find the rest of valence electrons available . Step 4 Distribute the remaining electrons in pairs so that each atom ends up with 8 e- (or 2 for H). First place lone pairs on the surrounding of the more electronegative atoms.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This homework help was uploaded on 04/20/2008 for the course CHEM 1300/ taught by Professor Ballester during the Fall '08 term at Nova Southeastern University.

Page1 / 2

LEWIS & VSEPR - Remember the first step to visualize a...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online