Which one is NOT an example of endothermic reactions? A. Fireflies release energy in the form of light
B. photosynthesis
C. Alka seltzer and water

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

jjj89t'ji; it hink the answer is your mom is not si

i think its 5049.

i hope this !

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante