Respuesta :

Answer:

Actinides

Explanation:

We need to Know what does it mean by elements being radioactive.

  • Radioactive elements  are elements whose atoms are not stable and therefore disintegrates to emit particles such as alpha, beta or gamma particles for them to attain stability.
  • In this case, elements known as Actinides are all radioactive.
  • Actinides are a series of radioactive elements in the group 3 of the periodic table. They include, thorium, uranium, plutonium, curium, etc.
  • Alkaline earth metals are elements in group II of the periodic table and most of them are not radioactive. Examples include, calcium and magnesium.
  • Halogens are group 7 elements in the periodic table. They are known to have an octet configuration. They include, Helium, neon, krypton, etc.

Answer:

b

Explanation:

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