an iron rod of length and diameter at 10 degree Celsius is used to measure a distance of 2 kilometre on a day when the temperature is 40 degree Celsius calculate the year error in measuring the distance.

The experiment was repeated many years later but the gases were mixed in a different type of container. a white solid was obtained which was xenon fluoride. predict whether you think 1) krypton and 2) radon will react with fluorine. explain reasons for your predictions

Ascientific blank must be testable and capable of being proven false?

Aball horizontally thrown from a cliff at 8m/s