which of the following involves a change in chemical properties?
mixing baking soda and vinegar to make bubbles of carbon dioxide
melting a bar of solid gold to make liquid gold
boiling water to make steam
tearing a piece of paper to make smaller pieces of paper

What happens to the atomic radius when an elctron is lost

Need what is special about water as a compound? how does water regulate climate? what drives water evaporation?   why is the water vapor fresh water when it rises from the ocean? why might freshwater in the form of snow take longer to enter the water cycle again than liquid precipitation?   what is an aquifer? what role do people play in the water cycle? plz just answer as many as you can ! thx if you !

1) a light bulb takes in 30 of energy per second. it transfers 3j as use energy. calculate the efficiency. second. it transfers 3j as useful light energy and 27j as heat energy. calculate the efficiency