Manned missions into the far reaches of outer space could require astronauts to be in weightless environments for years at-a-time. which of these is an effect of prolonged weightlessness on the human body?
a.
a stronger heart
b.
a loss of bone mass
c.
a weaker immune system
d.
a lack of sleep

Ahypothesis must be testable and falsifiable to be considered scientific a. trueb. false

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.

Which formula equation represents the burning of sulfur to produce sulfur dioxide? s(s) + o2(g) 4502(9) 2h2s(s) + 302(g) —> 2h20(0) + 2502(9) 4fes2+1102 —> 2fe2o3 + 8502 2802(g) + o2(9) v205 , 2503(9)