Question

The radioactive decay of uranium into thorium is represented by the equation
${}_{92}^{238}U\to {}_{90}^{234}Th+x$
What is x?

• A. an electron
• B. a proton
• C. an alpha particle
• D. a neutron

Answer 1

The correct option is C

an alpha particle

The mass number of x must be 238 - 234 = 4 and atomic number of x must be 92 - 90 = 2. Hence the correct choice is (c)