What does control group mean

How many joules of heat are absorbed to raise the temperature of 650 grams of water from 5.00c to it's boiling point, 100c

Tell me the iupac name of the following compounds:

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.