An 80.0 g sample of iodine-131 was placed in a sealed vessel forty days ago. Only 2.5 g of this isotope is now left. What is its half-life?

Which of the following is true of a heterogeneous mixture? a. Different samples may not be exactly alike. b. The density is the same throughout the entire mixture. c. It is not possible to separate the various parts of the mixture. d.

How many pair lone and unpair in electron in nitrogen, carbon and oxygen

How many electrons will fluorine gain or lose in forming an ion

Water from a lake changes to a gas state in the process of what?

A cylindrical glass tube 10.3 cm in length is filled with mercury (density = 13.6 g/mL). (The volume of a cylinder of radius r and length his V = arh.) The mass of mercury needed to fill the tube is 106.3 g. Calculate the inner diameter of the tube.

What are similarities between opinion based research and observation based research

What does your circulatory system transport?

What are the chemical components of a dna molecule?

Which type of reaction is described by the following equation? Na2O (s) + 2CO2 (g) + H2O (g) produces 2NaHCO3 (s)

According to Hund's Rule, if you were filling the three orbitals at the 2p energy level, you would first put an electron in the 2px orbital, then in the 2py orbital, and then in the 2pz orbital;