You cut a piece of wood and sand it to make a model. What kind of change occurred? A. chemical change B. substance change C. phase change D. physical change

Which relationship does EInsteins equation E = mc2 describe?

The convection that causes Earth's magnetic field happens in Earth's

Which one of the following is a trans fatty acid found in most snack foods?

Atoms in the chromosphere are not ionized. a. True b. False

Which of the following may indicate that a chemical reaction has occurred?

Is the water density higher than the aluminum density

How many moles of molecular oxygen (o2) are consumed in the complete combustion of one mole of pentane (c5h12) ?

A gas has a volume of 30 L at 105 kPa. What pressure is required to compress the gas to 21 L?

Using special equipment which layer of the sun atmosphere is visible during a total solar eclipse

The characteristic flame test colors of metal ions are due to atomic emission spectra. Duscuss the relationship between the absoption and emission of light and the factors responsible for flame test colors.