Forming a chemical bond releases energy and therefore is an exothermic process. Exothermic reactions usually feel hot because it is giving heat to you. Endothermic-a process or reaction that absorbs energy in the form of heat. Breaking a chemical bond requires energy and therefore is Endothermic.
karma level 71199. The Seikan Tunnel is a 53.85 km (33.46 mi) railway tunnel in Japan, with a 23.3-kilometre (14.5 mi) long portion under the seabed. Track level is about 140-metre (460 ft) below seabed and 240-metre (790 ft) below sea level. It is the longest undersea tunnel in the world, although the Channel Tunnel between the United Kingdom and France has a longer under-sea portion.
The Channel Tunnel: 20 fascinating facts. 1. The Channel Tunnel is 31.4 miles long, making it the 11th longest tunnel in use (the longest is the Delaware Aqueduct, at 85.1 miles), and the fourth longest used by rail passengers. It has the longest undersea portion of any tunnel in the world (23.5 miles).