Which of the following indicates an exothermic reaction?
O
O
A. A+B_heat , C+D
B. A + B + heat → C+D
C. A+B
→ C + D + heat
D. A + B + heat → C + D + heat

Which type of reaction always has an element and a compound as reactants

Asmall amount of a solid is added to water. the observation made after fifteen minutes is shown in the figure. which of these solids has been probably added to water? a) oil b) sand c) sugar d) wood chips

Compare the valence electron configuration of the nobles gas elements seen here. what statement is correct?