Which of the following atoms has 4 valence electrons

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?

What is avogadro’s number, and why is it useful

Free answer. the treaty of versailles ended world war i, but some of the terms of the treaty contributed to the beginning of world war ii. which was one of the terms of the treaty? the answer would be "germany was forces to pay reparations to the allied countries.". i hope this .