The half-life of radium-226 is 1590 years. if a sample contains 300 mg, how many mg will remain after 4000 years?

Determine the empirical formula for succinic acid that is composed of 40.60% carbon, 5.18% hydrogen, and 54.22% oxygen.

Which of the following statements about hybrid orbitals is or are true? choose all that apply. choose all that apply. under sp2 hybridization, the large lobes point to the vertices of an equilateral triangle. after an atom undergoes sp hybridization there is one unhybridized p orbital on the atom. the angle between the large lobes of sp3 hybrids is 109.5∘

Increasing the substrate concentration in an enzymatic reaction could overcome which of the following? a) the need for a coenzymeb) allosteric inhibitionc) competitive inhibitiond) insufficient cofactors