Que cambios son fisicos y cuales son quimicos?

a) quemar papel

b) limpiar objetos de plata

c) hacer hielo en el congelador

d) fundir hierro

A sample of fruit juice is found to have a hydrogen ion concentration of 2.87 x 10^-4 what would the pH be?

Ammonia and sulfuric acid react to form ammonium sulfate. Determine the starting mass of each reactant if 20.3 g of ammonium sulfate is produced and 5.89g of sulfuric acid remains unreacted.

A reaction in which energy is absorbed

According to current theory, a major reason for bonding is

Which best describes what forms in nuclear fission? A. two smaller, more stable nuclei B. two larger, less stable nuclei C. one smaller, less stable nucleus D. one larger, more stable nucleus

How many moles of NO3 are there in 6.2g

Which compound will conduct electricity when it is dissolved in water? a. CH4 b. CuSO4 c. C6H6 d. C6H12O6

Peter is 5 ft, 11 inches tall. Paul is 176 cm tall. Who is taller?

Which is the MOST accurate description about how the different types of feedback mechanisms work

What was one of the main benefits to the use of the icebox for cooling food?