Is this reaction endothermic or exothermic?

2Na2O2(s) + 2H2O(l) → 4NaOH(s) + O2(g) + 126 kJ

Suppose that during that icy hot lab 65,000 j of energy were transferred to 450 g of water at 20°c what would have have been the final temperature of the water

He table below gives the atomic mass and relative abundance values for the three isotopes of element m. relative abundance (%) atomic mass (amu) 78.99 23.9850 10.00 24.9858 11.01 25.9826 what is the average atomic mass (in amu) of element m? 2.86 5.36 24.30 24.98

At the current rate, a graph of carbon dioxide produced by fossil fuels over time would slope upward slope downward be horizontal be vertical