21% of oxygen in air with barometric pressure of 625. what's partial pressure

Why do "super glue" adhesives bond to skin?

While a certain isotope decays, it emits photons. What kind of decay is happening?

Which planet in our solar system is closest to the sun? A) Jupiter B) Earth C) Mercury D) Saturn

What is the concentration of a solution of (a) KOH for which the pH is 11.89; (b) Ca (OH) 2 for which the pH is 11.68

The Spleen is an organ that removes worn-out cells from the body.

In solid KCl, which has the same solid state structure as NaCl (simple cubic unit cell), the distance between the ions is 314 pm. Calculate the length of the edge of the unit cell.

Planck's constant is approximately equal to which of the following? The product of the uncertainties in electron position and electron momentum. The sum of the uncertainties in electron position and electron momentum.

Which is the MOST accurate description about how the different types of feedback mechanisms work

Which of the following equations violates the law of conservation of mass? A) 2Al + 6HCl yields 2AlCl3 + 3H2 B) Na2C2O4 + Pb (NO3) 2 yields PbC2O4 + 2NaNO3 C) AgNO3 + LiCl yields AgCl + LiNO3 D) 3Ca + 2Cr (NO3) 3 yields 3Ca (NO3) 3 + 2Cr

Which of the following is a true statement about energy? a. energy can be created and destroyed. b. energy is never created nor destroyed. c. energy is easily created, but cannot be destroyed. d. energy cannot be converted from one form to another.