B) hydrogen gas burns in air.
explanation: the rest are physical properties.
Answer:
A synthetic element is one of 24 chemical elements that do not occur naturally on Earth: they have been created by human manipulation of fundamental particles in a nuclear reactor, a particle accelerator, or the explosion of an atomic bomb; thus, they are called "synthetic", "artificial", or "man-made".
Explanation: hope that helps
The suffix -ene tells that there is a double bond present in the molecule, and the 2 tells where in the molecule the bond is located. The molecule looks like this:
CH3-CH=CH-CH3
-ane indicates single bonds
-ene indicates at least one double bond
-yne indicates at least one triple bond
