Which one of the following is not a balanced equation? explain why.
a. c3h8 (g) + o2 (g) → co2 (g) + h2o (g)
b. c3h8 (g) + 5o2 (g) → 3co2 (g) + 4h2o (g)
c.2mg (s) + o2 (g) → 2mgo (s)
d.4na (s) + o2 (g) → 2na2o (s)

Suppose a lab group reports a ppercent yield of sand of 105. is it really possible to collect more sand than was originally represented? what is the possible explanation for the extra product?

Which of the following natural processes is most likely to support the formation of an underwater sinkhole? a pollution buildup from deposited minerals b limestone cave collapsing due to changes in sea level c erosion of large amounts of sand moved by ocean waves d oxidation of rock formed by chemical weathering

The ozone molecule o3 has a permanent dipole moment of 1.8×10−30 cm. although the molecule is very slightly bent-which is why it has a dipole moment-it can be modeled as a uniform rod of length 2.5×10−10 m with the dipole moment perpendicular to the axis of the rod. suppose an ozone molecule is in a 8000 n/c uniform electric field. in equilibrium, the dipole moment is aligned with the electric field. but if the molecule is rotated by a small angle and released, it will oscillate back and forth in simple harmonic motion. what is the frequency f of oscillation?