The Earth moves in predictable patterns. One of these patterns causes approximately 12 hours of daylight and 12 hours of darkness during a 24-hour
period in areas around the equator. This movement is referred to as -
A. a rotation
B. an equinox
C. a photoperiod
D. a revolution

Motivation cannot be developed with practice; a person either possesses it or they do not.

How air particles exert a pressure on the inside of the balloon

For a research project, a student decided to test the effect of the lead(ii) ion (pb2+) on the ability of salmon eggs to hatch. this ion was obtainable from the water‐soluble salt, lead(ii) nitrate, which the student decided to make by the following reaction. pbo(s) + 2 hno3(aq) → pb(no3)2(aq) + h2o losses of product for various reasons were expected, and a yield of 86.0% was expected. in order to have 5.00 g of product at this yield, how many grams of pbo should be reacted? (assume that sufficient nitric acid, hno3, would be used.)