Question

of the following kinds of electromagnetic waves, which two can be damaging to human tissue?
ultraviolet
gamma rays
infrared
radio

Explanation:

• Ultraviolet (UV) rays have enough energy to damage DNA in human cells, increasing the risk of skin cancer and causing sunburn.
• Gamma rays are highly energetic and can penetrate deep into the body, ionizing atoms and molecules in human tissue. This ionization can break chemical bonds in DNA, proteins, and other biological molecules, leading to cell damage, mutations, and potentially cancer.
• Infrared radiation is mainly felt as heat. While excessive heat from intense infrared sources (like extremely hot objects) can cause burns, it's not as inherently damaging to human tissue at typical environmental levels as UV and gamma rays in terms of direct cellular/molecular damage (like DNA - level damage).
• Radio waves have very low energy. They are non - ionizing radiation and do not have enough energy to break chemical bonds in human tissue. They are used in communication (e.g., radio, TV, mobile phones) and are generally considered safe at normal exposure levels.

Answer:

ultraviolet, gamma rays