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.
Report Abuse. As long as you need them. Sorry, not trying to be a wise-guy with that. Tax documents such as payroll stubs, cancelled checks for deductible items, etc. 3 years from the end of the year in which the taxes were due. Best to keep them for 5 years, however. Pay stubs (or W-2s) and possibly tax returns should be kept forever if you think you may need proof of income for Social Security purposes. Real estate documents: As long as you own the property + 3 - 5 years for tax purposes. Other receipts: As long as the warranty runs, for proof of purchase.