Which of these represents a physical change? a iron rusting b ice melting c wood burning d food spoiling

Which gas is both colorless and odorless?

What can be determined from examining the fossil record? A. when changes to the diversity of life forms occurred B. when many life forms first appeared on earth C. when many life forms became extinct D. all of the above

3.9 X 1022 molecules of CO2 = _ moles of CO2

Compare and contrast the general properties of alloys and pure metals

How many sig figs are in 1401.00

Most modern forms of transportation are powered by fossil fuels. Carbon dioxide, methane, carbon monoxide, and other gases are released into the atmosphere during the production and combustion of these fuels.

Does the reaction of a burning candle give off or absorb heat

1. Describe the difference between valence and core electrons.

How are deltas and rivers similar?

You plan to separate a polar and a non-polar compound using normal phase column chromatography technique. Methylene chloride (CH2Cl2) and hexanes (C6H14) are the solvents to be used to elute the column. Which solvent should be used first