The vertical columns are groups
The horizontal rows are periods
Answer: A. It can identify the elements in the sample.
Explanation: on edge
Hello!
The reaction that the graph represents is
A. Exothermic because Hrxn=-167 kJTo calculate Hrxn we apply the following equation:

Looking at the graph, and at the result of the calculations, we can see that the enthalpy of the products is
lower than the enthalpy of the reagents, because the sign is negative. That means that the reaction
releases energy in the form of heat and that the reaction is
exothermic.
Have a nice day!
Answer:
well there is no chose here is my best option i would chose
1 Electronegativity is the ability of an atom to attract electrons.
Explanation: