A sample of a radioactive isotope initially contains 20 x 10^10 atoms. After 16 days, 5 x 10^10 atoms remain. what is the half-life of the isotope?

A) 12 days

B) 20 days

C) 10 days

D) 16 days

E) 8 days

What is precision in chemistry

If a certain gas occupies a volume of 10. L when the applied pressure is 5.0 atm, find the pressure when the gas occupies a volume of 2.5 L. Express your answer to two significant figures and include the appropriate units.

True or false climatologist use weather balloon stethoscope and satellite

Which organ (s) would be responsible for this trait? Select two options.

If you have 7.73 g of H 2, how many grams of N H 3 can be produced?

The absorbance of a chlorophyll a standard solution in ethanol (density = 0.785 g/mL) is measured in a 1.3 cm cuvette or path length. The absorbance is 0.765 and the molar absorptivity coefficient is 86,300 M-1cm-1.

How does the surface of the earth change slowly over time

For metalloids on the periodic table, how do the group number and the period number relate? A. The lower the group number, the lower the period numbers, so the metalloids are found in a diagonal moving down from left to right. B.

To name the compound written as CuCl2, you would write: O A. Copper chloride. O B. Chromium (II) chloride. O O C. Copper (II) chloride. D. Copper fluoride.

Two parents who are both GG for a gene are crossed. what is the genetic makeup of the offspring. A. gg B. gG C. GG D. Gg