Why does the color of tomatoes turn red when ripe?

Radio waves are reflected from which part of the atmosphere-

When the snowflake melts, the result will be-

The rotations per second of a wheel that spins at an accelerating rate are measured by

Due to the increase in the amount of carbon dioxide in the atmosphere-

Who invented the rabies vaccine?

Raindrops are spherical-

In what form is phosphate found in bones?