Group 2, or in the Alkaline Earth Metals section. This is due to the necessity to have a +2 charge to balance out or negate the -2 charge two Bromines carry.
Mutualism! The tree provides a home and food for the ants, while the ants protect the tree :)
Much of biological studies are actually chemistry because of chemical changes that occur within organisms. Similarly, large parts of chemistry are governed by physics.
Cathode rays are a stream of negatively charged particles or electrons in vacuum tubes. They were first seen by Johann Hittorf in 1869. They are named since they are emitted by electrode or cathode. In order to release the electrons, the electrons should first be detached from the atoms of the cathode.
The ability to attract an electron for bonding is called (option B) Electronegativity.
