What do all isotopes of an element have in common

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Athermometer is removed from a room where the temperature is 70° f and is taken outside, where the air temperature is 10° f. after one-half minute the thermometer reads 60° f. what is the reading of the thermometer at t = 1 min? (round your answer to two decimal places.) ° f how long will it take for the thermometer to reach 30° f? (round your answer to two decimal places.)

Which features on mars point to the possibility of liquid water on the planet? impact craters with sharp rims volcanic cones with craters gullies and stream-like channels mountain ranges with faults