What is modern methods of agriculture practices and its advantages?

Which statement would indicate the presence of an acid

In a laboratory determination of the atomic weight of tin, a sample of tin is weighed in a crucible. nitric acid is added, and the reaction proceeds to give a hydrated tin(iv)oxide plus no2and h2o. the hydrated tin(iv)oxide is then heated strongly and reacts as follows: sno2.xh2o(s)sno2(s)+ xh2o(g)the sno2is finally cooled and weighed in the crucible. explain the effect on the calculated atomic weight of tin that would result from each of the following experimental errors: (a)considerable spattering occurs when the nitric acid is added to the tin.(b)the hydrated tin(iv)oxide is not heated sufficiently to change it completely to tin oxide.

The concentration of ionic substances is important for the heart to beat. your heart responds to electrical impulses that travel through heart cells that are made up mostly of water. which properties of ionic compounds are important to support this function? solubility in water conductivity crystalline melting point