Compare and contrast O2 and F2.

Groups of organs that work together to complete a process in the body are called: a. cells b. tissues c. nerves d. systems

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies.

If an atom contains 11 protons in its nucleus, predict the element with the atomic number and electronic configuration. will the number of electrons remain the same during the chemical reaction in such an atom? explain.