What is the half-life of a radioisotope if 25.0 grams of an original 200.-gram sample of the isotope remains unchanged after 11.46 days?

(1) 2.87 d (3) 11.46 d

(2) 3.82 d (4) 34.38 d

Why is heat acclimatization important? select all that apply?

Do plants uptake phosphorus as P?

What is the charge of an ion that has 12 protons and 13 electrons

Use a periodic table to answer this question. how many grams of co2 are in 2.1 mol of the compound?

The energy needed to melt 1 g of a substance is called the

Identify the spectator ions in the following complete ionic equation. 2k (aq) s2 - (aq) pb2 (aq) 2no-3 (aq) →pbs (s) 2k (aq) 2no-3 (aq) express your answers as ions separated by a comma.

4. A bird left its post and flew in a triangular path. It flew 21 yards south, 72 yards east and 75 yards diagonally to end back at the post. Is it a right triangle?

Condension occurs in the inside of your windows in Winters, why?

How can you use Hess's law to determine a reaction's enthalpy?

7. How much energy in KJ is released when 15.0 g of steam at 100.0 degrees Celsius is condensed and then frozen to ice at 0.0 degrees Celsius?