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.
WHAT TO KEEP. The most important documents to hang on to are your annual tax returns. You should keep the actual returns forever, but you can get rid of the supporting documents after three years. That's how long the IRS has to initiate an audit.Once the time elapses, toss the records -- and shred any that reveal your Social Security number or other personal information.nother reason to keep these papers: If you sell your house at a hefty profit (more than $500,000 for couples filing a joint return or $250,000 for single filers), certain expenses can be used to lower your tax bill. After you sell the house, keep the documents for three years.