A Rock is determined to be 1.426 billion years old. How much uranium-235 remains in the rock?

Many radioactive atoms that have large masses undergo radioactive decay by releasing a particle that is identical to a helium-4 nucleus. what changes in the original atom are expected as a result of this natural phenomenon? the atomic number and the mass number will decrease. the atomic number and the mass number will increase. the atomic number will increase, and the mass number will decrease. the atomic number will decrease, and the mass number will increase.

Which question comparing two different metals is best answered through science? a. which metal is easier to use? b. which metal is harder to find? c. which metal is less dense? d. which metal is more valuable?

Acompound consisting of b, n, and h undergoes elemental analysis. the % composition by mass is found to be 40.28% b, 52.20% n, and 7.53% h. what is the empirical formula for this molecule? enter in the empirical formula in the form bxnyhz