Is Na+H20 -> H2+ NaOH a single replacement, Double Replacement or A Decomposition reaction

Water (2510 g ) is heated until it just begins to boil. if the water absorbs 5.09×105 j of heat in the process, what was the initial temperature of the water?

In what way do investigations build scientific knowledge? the results of investigations lead to questions that cannot be tested. they reflect the opinions and social values of scientists, ensuring valid information. the results of investigations lead to new questions, which lead to new investigations. they are not influenced by the research of earlier scientists, so they are able to address gaps in understanding.i

Which is true according to the law of conservation of energy