The first step in the decay chain of 232 90th is an alpha decay. what is the daughter nucleus formed by this first decay?

Answer is: the daughter nucleus formed by this first decay 228/88Ra.

Alpha particle is nucleus of a helium-4 atom, which is made of two protons and two neutrons.
Nuclear reaction: ²³²Th → ²²⁸Ra + α (alpha particle).

Alpha decay is radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and transforms into an atom with an atomic number that is reduced by two and mass number that is reduced by four.

right

explanation:

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.