TNT/BS

Java Edition:

Name	Default value	Allowed values	Description
unstable	false	false	Hitting the TNT block breaks it, dropping it as an item that can be picked up.
		true	Hitting the TNT block causes it to ignite and then explode.

Bedrock Edition:

Name	Metadata Bits	Default value	Allowed values	Values for Metadata Bits	Description
allow_underwater_bit	0x2	false	false	0	This is normal TNT.
			true	1	This is Underwater TNT.
explode_bit	0x1	false	false	0	Hitting the TNT block breaks it, dropping it as an item that can be picked up.
			true	1	Hitting the TNT block causes it to ignite and then explode.