Which statement describes a physical change? * A. An iron bolt on a bridge rusts and weakens the bridge.
B. The surface of a silver cup turns black when it is exposed to air.
C. A sculptor casts a statue in molten bronze and allows it to harden.
D. Slivers of magnesium in fireworks form a bright glow as they burn.

Aside from human impact, which of the following causes less water vapor production over a small area? (2 pderivartin

If 34.2 grams of lithium react with excess water, how many liters of hydrogen gas can be produced at 299 kelvin and 1.21 atmospheres? 2 li (s) + 2 h2o (l) yields 2 lioh (aq) + h2 (g)

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line