A scientific theory provides an explanation of observed phenomenon. An example of a scientific theory would be?
3
O Darwin's theory of evolution.
O Walker's theory of attendance.
O Newton' law of motion.
O Hubble's law of cosmic expansion.

At 450 mm hg a gas has a volume of 760 l, what is its volume at standard pressure

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.

Asample of hydrated tin (ii) chloride (sncl2) has a mass of 4.90 g. when it is dehydrated, it has a mass of 4.10 g. which is the correct chemical formula for the hydrate? sncl2•2h2o          sncl2•4h2o          sncl2•6h2o