How did ancient people build massive structures such as the pyramids in Egypt and Stonehenge?

Asolution at 25 degrees celsius is 1.0 × 10–5 m h3o+. what is the concentration of oh– in this solution?

How will the emission of an alpha particle affect the atomic number of an atom

1. explain hydrogen peroxide, h 2 o 2 properties and decomposition reaction. 2. describe how each of the following natural cycles plays a part in earth’s climate system. (a) the water cycle (b) the carbon cycle