Final answer:
High-mass stars do have a helium flash, which is a rapid onset of helium fusion in their core. However, fusion stops after the helium is exhausted. High-mass stars can fuse elements heavier than carbon and their life ends with a supernova explosion.
Step-by-step explanation:
The statement 'High-mass stars do not have a helium flash' is incorrect. When low-mass stars become red giants, they undergo a rapid onset of helium fusion in their core, which is known as the helium flash. However, in stars with masses about twice that of the Sun or less, fusion stops after the helium in the core is exhausted. Fusion of hydrogen and helium in shells around the contracting core makes the star a bright red giant again, but only temporarily.
On the other hand, high-mass stars have a different evolution. After the helium in their core is exhausted, the weight of the outer layers forces the carbon core to contract and become hot enough to fuse carbon into heavier elements like oxygen, neon, magnesium, silicon, sulfur, calcium, and argon. These elements can further combine to produce iron. Therefore, high-mass stars can fuse elements heavier than carbon and, in fact, undergo fusion reactions involving oxygen and still heavier elements.
Additionally, the life of a high-mass star ends with a supernova explosion, which is another characteristic that sets them apart from low-mass stars.