Procedure. 1  Start with a short lecture on the nature of solid, liquid, and gaseous water. 2  Your goal is to give some understanding that water molecules themselves don't change when the state of the matter changes, but that the interaction between molecules changes.
Check out our guide of what to toss when. Is your important paperwork piling up? Check out our easy-to-use chart to see what to keep, what to toss, and how to store those hard-to-replace documents. Keep tax returns, as well as supporting documents like W-2 forms, receipts, and real estate closing statements for seven years.
As a result, you will need to keep your 2008 tax return and related papers until April 2012. It's generally safe to shred and discard it after that (unless a situation described below applies to you). See IRS Publication 552, Recordkeeping for Individuals, for more information. Six Years. If you may have under-reported income by 25 percent or more, then you'll need to keep tax returns and all related information for six years. When there is substantial activity from a closely held business, or the cost basis records for property or securities sold are unclear, under-reporting income is a real possibility.