What can be observed about a substance that does not change the identity of that substance

Would kg, ml, or cm signify a measurement of weight?

The half-life of radon-222 is 3.8 days. If a sample currently contains 3.1 grams of radon-222, how much radon-222 did this sample have 15.2 days ago? a 12.4 grams b 47.1 grams c 49.6 grams d 57.8 grams

In order for a substance to change from a liquid to a gas, heat must be taken away heat must be added heat could be either added or taken away heat must be kept constant

You are told to take 2 grams of advil a day. how many milligram tablets does that equal

What is the best way to reduce the activation energy?

Which of the following likely formed Mars' moons?

Which process involves mass movement within a substance? a. conduction b. convection c. radiation d. reflection

A scientist observes that the electrical resistance of a superconducting material drops to zero when the material is cooled to very low temperatures. Which of the following statements best describes what the scientist is observing?

Which describes an object's speed in free fall? a. The object accelerates until it reaches its terminal velocity. b. The object falls at a constant speed because only one force acts on it. c.

Which metal can be cutted easiy?