Why is it necessary to immerse the flask both in hot and cold water for 5 minutes before taking the temperature?

What does the symbol (–hfus) indicate in a phase change?

What rule is used to determine how many covalent bonds an element can form? a. the number of covalent bonds is equal to six c the number of covalent bonds is equal to five minus the group number plus the group number b. the number of covalent bonds is equal to eight d. none of the above minus the group number select the best answer from the choices provided

What is the value of the standard enthalpy of formation of an element in its most stable form?