when the gas in a balloon is heated, the balloon expands. what are the correct signs of heat and work for this change?
a. +q, -w
b. -q, +w
c. +q, +w
d. -q, -w
things that could :
w=work q= heat
q= heat work
+ heat absorbed + work done by
- heat released - work done on

Sodium chloride, nacl, is formed when a sodium atom transfers its electron to a chlorine atom. the difference in charge between the two atoms creates a(n) attraction that bonds them together.

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.

You are doing a science experiment with a fahrenheit thermometer. your data must be in degrees celsius. if you measure a temperature of 125°f, what is this temperature in degrees celsius