Most organic compounds are made of just four elements. What are they?

Choose four answers.

•nitrogen
•hydrogen
•oxygen
• helium
• carbon
• sodium

Why doesn't heat added to water make the tempature rise above 100c

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

How many grams of aluminum will there be in 98g of al2o3?