After a radioactive atom decays, it is the same element that it was before with no measurable change in mass. which kind of decay has occurred, and how do you know? a) alpha decay because alpha particles have no mass b) beta decay because this kind of decay cannot change one element into another c) alpha decay because it creates a new isotope of the same element d) gamma decay because photons have no mass

D)  Gamma decay because photons have no mass

Explanation:

1) Gamma ray emission: It is a decay process in which an unstable nuclei gives excess energy in the form of electromagnetic radiations[/tex]. This process does not lead to change in mass number.

2) Alpha Decay: In this process, a heavy nucleus decays into lighter nucleus by releasing alpha particle or a helium atom. The mass number is reduced by 4 units.

3) Beta decay:  It is a type of decay process, in which a neutron turns into a proton and release a electron. In this the atomic number decreases by one  and hence a new element gets formed. The mass number remains same.

the correct answer is answer a. a mixture

no other options make sense

hope this

have a great day : )

  - sprinkles

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :