What factors can affect the cleanliness of the water in lakes and rivers? How important is it
to keep the water in lakes and rivers clean?

The ratio pv to nrt is plotted against pressure for ch4 at 0°c and 200°c. why does the curve for 0°c drop below the horizontal line for an ideal gas whereas the curve for 200°c does not?

Rectangle pqrs has length a and width 4b. the x-axis bisects ps and qr what are the coordinates of the vertices

There are 15 plates and each plate is either 7 or 12 inches diameter. which systems of equations do you use to find the number of 7 inch plates, x and 12 inch plates, y