A scientist wants to perform a reaction in a vacuum chamber to control the experiment as much as possible and to prevent other variables from impacting the reaction. The scientist is trying to determine if the reaction is endothermic or exothermic and measure how much energy is absorbed or given off. Is this a sound approach? Why or why not? In three to five sentences, explain your reasoning. (4 points)

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.