A student investigated the rate of reaction between calcium carbonate (marble chips) and hydrochloric acid
The student had collected 30 cm of gas produced after 15 seconds. Calculate
the mean rate of reaction from 0 to 15 seconds

Click the button that shows the correct relationship of the electron affinities of the elements sodium and phosphorus. sodium’s electron affinity value is more negative than the electron affinity value of phosphorus. phosphorus’ electron affinity value is more negative than the electron affinity value of sodium. this information cannot be determined using the periodic table. answer is b on e2020.