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a radioactive particle that is made up of two protons and two neutrons

An alpha particle is a radioactive particle that is made up of two protons and two neutrons.

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a He2+ ion or the helium nucleus

An alpha particle is a He2+ ion or the helium nucleus.

a highly charged helium nucleus (), two protons and two neutrons

Instead of a lightweight electron, an alpha particle is a highly charged helium nucleus (two protons and two neutrons), about 8,000 times as massive and delivering all all its considerable kinetic energy's considerable kinetic energy over a few micrometers.

a helium nucleus, which is the He2+ ion

An alpha particle is a helium nucleus, which is the He2+ ion.

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2 protons and 2 neutrons () i.e. a helium nucleus

An alpha particle is 2 protons and 2 neutrons (i.e. a helium nucleus).

a type of particle radiation that is made up of two protons and two neutrons bound together

An alpha particle is a type of particle radiation that is made up of two protons and two neutrons bound together.

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just a helium nucleus without any electrons -- two protons and two neutrons

An alpha particle is just a helium nucleus without any electrons -- two protons and two neutrons.

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a helium nucleus consisting of two protons and two neutrons all strongly bound together by nuclear forces

An alpha particle is a helium nucleus consisting of two protons and two neutrons all strongly bound together by nuclear forces.

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a helium-4 nucleus () 2 protons and 2 neutrons, designated by \(\alpha\

An alpha particle is a helium-4 nucleus (2 protons and 2 neutrons, designated by \(\alpha\) or \(_2^4He\), which are extremely tightly-bound to each other).

a combination of two protons and two neutrons, which if you know your periodic table you’ll recognize as a helium nucleus

An alpha particle is a combination of two protons and two neutrons, which if you know your periodic table you’ll recognize as a helium nucleus.