Potassium-40 has a half-life of 1.277 x 109 years. After 1.022 x 1010 years, how much potassium-40 will remain from a 500.3-g sample?

A. approximately 1.95 g

B. approximately 3.91 g

C. approximately 62.54 g

D. approximately 71.47 g

Difference between nitrogen 14 and nitrogen 15

What is the mass number of beryllium with 5 neutrons

Flammability is an example of what? A. chemical property B. physical property C. dangerous substance D. atomic bond

For the reaction A (g) → 2 B (g), K = 14.7 at 298 K. What is the value of Q for this reaction at 298 K when ∆G = - 20.5 kJ/mol?

Consider mixing 25.00 mL of 0.0200 M of each of the following of solutions. In which of the following will a precipitate form: Na2SO4 mixed with Ba (NO3) 2 NH4Cl mixed with Mg (NO3) 2 KF mixed with Ba (NO3) 2 MgCl2 mixed with Na2CO3

Samuel adds a teaspoon of salt to a glass of water. He notices that the song disappears. Samuel takes a sip to discover that the water taste salty. What kind of change has occurred?

How are the physical and chemical properties of atoms represented on the periodic table of elements

how do we know isotopes exist?

Is albinism a dominant or recessive trait

If T = dominant, and t = recessive, what would the genotypes be?