Answer: Physical properties
Explanation: Can be measured without changing a substance's chemical identity.
substitute: <span><span>t<span>1/2</span></span>=<span><span>ln(2)</span>k</span>→k=<span><span>ln(2)</span><span>t<span>1/2</span></span></span></span>
Into the appropriate equation: <span>[A<span>]t</span>=[A<span>]0</span>∗<span>e<span>−kt</span></span></span>
<span>[A<span>]t</span>=[A<span>]0</span>∗<span>e<span>−<span><span>ln(2)</span><span>t<span>1/2</span></span></span>t</span></span></span>
<span>[A<span>]t</span>=(250.0 g)∗<span>e<span>−<span><span>ln(2)</span><span>3.823 days</span></span>(7.22 days)</span></span>=67.52 g</span>
The correct option is A.
Climate refers to the long time pattern of weather condition in a particular area. Climate is measured by assessing the patterns of variation in temperature, relative humidity, wind, atmospheric pressure, precipitation and other meteorological variables in a given area over a long period of time.<span />
Molecules in the paper react differently with Hydronium and Hydroxide.
pH paper deals with acidity and basicity of something. You are correct in thinking that A is the answer. Always go with your gut. don't be like me when I was in college who always second guessed my answers. Good luck with chemistry.