We've discovered many exoplanets that are many light years away. Why don't these planets orbit the Sun?

A248-g piece of copper is dropped into 390 ml of water at 22.6 °c. the final temperature of the water was measured as 39.9 °c. calculate the initial temperature of the piece of copper. assume that all heat transfer occurs between the copper and the water. remember, the density of water is 1.0 g/m

To a of 4 x hz is 1. 0. mm nm nm

Why is the use of carbon-14 limited