$\beta$ - Decay of Tritium

Tritium is an isotope of hydrogen with one proton and two neutrons. A hydrogen-like atom is formed with an electron bound to the tritium nucleus.The tritium nucleus undergoes $\beta$ decay, and the nucleus changes its charge state suddenly to $+2$ and becomes an isotope of helium. If the electron is initially in the ground state in the tritium atom, what is the probability that the electron remains in the ground state after the sudden $\beta$ decay $?$