Muscle tissue is made up of cells that contract and release to produce movement. which process provides the energy that the cells need to contract?
a. respiration
b. meiosis
c. photosynthesis
d. mitosis

The tilt of the earth's axis of rotation is responsible for the a) ocean's tides. b) size of the moon. c) brightness of stars. d) earth’s seasons.

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.)

If you burn 46.6 g of hydrogen and produce 416 g of water, how much oxygen reacted