Why do people put on sunscreen to protect from ultraviolet light but don't try to protect
themselves from infrared light? refer to em spectrum to answer

Which of these is a physical property

Scientists often have to deal with numbers that are either very large or very small. for example, the radius of the sun is approximately 696,000 kilometers, while bacterial cells are as small as 1.9 × 10-4 millimeters. express each number in an alternate form.

The kw for water at 0 °c is 0.12× 10–14 m2. calculate the ph of a neutral aqueous solution at 0 °c.