When scientists say that a theory can never be proven , what are they actually saying?

Clouds form when water vapor to form small droplets. a. humidifies b. condenses c. evaporates d. precipitates

Urea, co(nh2)2, is manufactured on a large scale for use in producing urea-formaldehyde plastics and as a fertilizer. what is the maximum mass of urea that can be manufactured from the co2 produced by combustion of 1.00 x 104 grams of co2?

Check the correct box to describe the periodic trends in electronegativity. electronegativity across a period: decreases. increases. electronegativity down a group: decreases. increases.