A sample contains 9,000 particles of the original isotope for every 63,000 particles of the daughter isotope. The half-life of the original isotope is 19 years. Find the age of the sample.

Describe the interaction that occurs between two objects with the same electrical charge.

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange

Which of the following is most likely true about water in chemical systems? a) water dissolves nonpolar ionic compounds. b) water dissociates ionic compounds. c) water dissociates covalent molecules. d) water dissolves nonpolar covalent substances.