If half-life of thallium-208 is 2.35 days, how many days will it take for a 180g sample of thallium-208 to decay to only 22.5g?

Complete the sentence. the lower the hydrogen ion concentration, the the ph. higher lower closer to 7 closer to 0

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.

Complete the following statements to describe solids, liquids, and gases. select the correct answer from each drop-down menu. a solid a definite volume and a definite shape. a liquid a definite volume and a definite shape. a gas a definite volume and a definite shape