Para remplazar y el resultado por favor (p V r) ↔ (r ∧~s)

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

Nitrogen (n), phosphorus (p), and potassium (k) are the main nutrients in plant fertilizers. according to an industry convention, the numbers on the label refer to the mass percents of n, p2o5, and k2o, in that order. calculate the n: p: k ratio of a 30: 10: 10 fertilizer in terms of moles of each element, and express it as x: y: 1.0.

Using data from seismic waves, geologists have learned that earth’s interior is made up of several