La alegría es la vacuna para eliminar la tristeza, pero para obtenerla, ¿qué se debe hacer? Explica:​

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

Positrons are spontaneously emitted from the nuclei of

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron