Final answer:
Rays, specifically UVB rays from the sun, are helpful to humans in the production of vitamin D. However, excessive exposure to rays, particularly UVA rays, can be harmful to the skin and increase the risk of skin cancer.
Step-by-step explanation:
Rays, specifically UVB rays from the sun, are helpful to humans in the production of vitamin D. When UVB rays strike the skin, a reaction occurs that enables the body to synthesize vitamin D. This vitamin plays a crucial role in calcium absorption and bone health.
However, it is important to note that excessive exposure to rays, particularly UVA rays, can be harmful to the skin and increase the risk of skin cancer. Therefore, it is important to protect the skin from these harmful rays by wearing sunscreen or seeking shade.
Learn more about The benefits and risks of rays to humans