What is the total number of electrons in the second energy shell of a calcium atom in the ground state

8 electrons

Explanation:

The atomic number of calcium (ca) is 20. Therefore,

in the first shell the number of electrons are 2

in second shell the number of electrons are 8

in the third shell the number of electrons are 8

in the fourth shell the number of electrons are 2

electronic configuration in ground state:

1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2

Hope it helps u (｡◕‿◕｡)

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 :