Which change occurs when an atom undergoes alpha decay? The nucleus loses mass and a new element is produced.
The nucleus gains a proton and a new element is produced.
The nucleus loses energy and remains the same element.
The nucleus loses a neutron and remains the same element.

In alpha decay, an alpha particle (a helium nucleus) is emitted from the radioactive atom, and the atom therefore loses
2 protons, and becomes a new element.

Loss of Small Particles from the Nucleus

The nucleus of an unstable isotope can lose one of several particles:
Neutron (n)
Loss of a neutron gives a different isotope of the same element. The atomic number (number of protons, determining the element) remains the same but the atomic mass reduces by about 1 amu.

Alpha particle ()
An alpha particle is a helium nucleus, 2 protons and 2 neutrons, loss of an alpha particle give a new element with an atomic number 2 less than the original isotope and an atomic mass that is lower by about 4 amu.

Beta minus particle ()
This is an electron. An electron can be lost from the nucleus when one of the neutrons in that nucleus splits into a proton and an electron. Beta decay forms a new isotope with an atomic mass greater by 1 than the original isotope but the atomic mass is nearly unchanged.

Beta plus particle ()
This is a positron and it results from a proton in the nucleus splitting into a positron and a neutron. When the positron leaves the nucleus it always collides with an electron, annialating both in a burst of gamma radiation. Loss of a beta plus particle gives a new element with an atomic number 1 less than the original isotope and an atomic mass that is nearly unchanged.

Hope all these helps

That depends on what kind of environ meant it is in  in space it has the same force that was applied when the velocity was gained