¿Cuál de las siguientes representa una reacción química sencilla? al separar el agua de la arena mediante un embudo

al preparar caramelo a partir de azúcar y agua

cuando mezclamos vinagre con agua en un vaso de precipitado

cuando evaporamos el agua en una mezcla de agua salada​

all matter is made up of atoms

in any element all atoms are the same

elements in a compound are always in a constant ratio: apex

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.

sex cells are usually half's then they find another half and make a fertilize egg

answer: 20 percent

the fish culture has become a developing commercial practice in developing countries which is already prominent in developed countries of the world. the major fish protein demand is being supplemented in developing countries is   fishing to meet the needs of the growing population. therefore, in some developing nations, the percentage of animal protein from fish in the diet can be as high as 20 percent.