(chemistry) a series of 15 radioactive elements with increasing atomic numbers from actinium to lawrencium

(chemistry) a series of 15 radioactive elements with increasing atomic numbers from actinium to lawrencium

(chemistry) a series of 15 radioactive elements with increasing atomic numbers from actinium to lawrencium

(chemistry) a series of 15 radioactive elements with increasing atomic numbers from actinium to lawrencium

(chemistry) a series of 15 radioactive elements with increasing atomic numbers from actinium to lawrencium

any of a series of radioactive elements with atomic numbers 89 through 103

any of a series of radioactive elements with atomic numbers 89 through 103

any of a series of radioactive elements with atomic numbers 89 through 103

any of a series of radioactive elements with atomic numbers 89 through 103

any of a series of radioactive elements with atomic numbers 89 through 103