To which radioactive families do the following nuclides belong?
`.^(222)Rn`, `.^(228)Ra`, `.^(307)Pb`, `.^(209)Bi`, `.^(233)Pa`

To which of the following family do folic acid and pentothenic acid belong

Which of the following elements do not belong to the family indicated ?

In ._92U^(238) radioactive series by alpha decay or beta decay, which one of the following can be the end product: Pb^(206),Pb^(207),Pb^(208),Pb^(209) ?

Under certain circumstances, a nucleus can decay by emitting a particle more massive than an alpha -particle. Consider the following decay processes: ._(88)Ra^(223)to._(82)Pb^(209)+._(6)C^(14) , ._(88)Ra^(223)to._(86)Rn^(219)+._(2)He^(4) (a) Calculate the Q-values for these decays and determine that both are energetically allowed.

In the thorium decay series that begins with .^(232)Th,.^(228)Th alpha-decays into .^(224)Ra with a half life of 1.9yr. .^(224)Ra alpha-decays into .^(230)Rn with a half life of 3.7d, which in turn decays into .^(216)Po with a half life of 55s. If the nuclides are in radioactive equilibrium in a mineral sample that contains 1.0g of .^(220)Rn , what are the masses of .^(224)Ra abd ,^(228)Th in the sample?

Which of the following element is an isodiapher of ._(92)Pb^(212) ? a ._(92)U^(235) b. ._(90)Th^(231) c. ._(83)Bi^(209) d. ._(91)Pa^(231)