How many joules of heat are needed to raise the temperature of 20g of aluminum from 54^\circ ∘ c to 82^\circ ∘ c, if the specific heat of aluminum is 0.540 j/gc a. 302.4 j b. 29 j c. 1037 j d. 0.76 j

8) a mixture of he, ne and ar has a pressure of 7.85 atm. if the ne has a mole fraction of 0.47 and 8) ar has a mole fraction of 0.23, what is the pressure of he? a) 4.2 atm b) 3.7 atm c) 5.5 atm d) 2.4 atm e) 1.8 atm

Displacement is the slope of a velocity vs. time graph a. true b. false

The characteristics of two different types of reactions are shown below: reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of an element. which statement is true about the atoms of the elements that participate in the two reactions? their identity changes in both reaction a and reaction b. their identity changes in reaction a but not in reaction b. their identity changes in reaction b but not in reaction a. their identity remains the same in both reaction a and reaction b.