Which is not a clue that a chemical change has taken place? a)changes color when heated b)boils at 90°c c)bubbles in water d)disappears in acid

Mike and mitchell decide to have a foot race. they mark off a stretch of 100 yards, and recruit cindy to work the stopwatch. after running the race and looking at the results, cindy declared that mitchell was the fastest. so how did the boys times compare?

Ants live on acacia trees in south america. the ants feed on sugars secreted by the trees. the trees provide room for the ants to live. the ants sting any other insect or animal that comes to eat the trees. what type of relationship is this?

11) burning your hand when accidentally touching a hot plate is an example of which heat transfer? a. conduction b. convection c. radiation d. none of these