Fluorine, iodine and bromine are all in the same group. Fluorine been the first element in the group has less number of electron orbitals compare with bromine and iodine. Bromine and iodine has D orbitals which can take part in their bonding activities, this allows the elements to bond in a variety of ways, but fluorine does not have the D orbital and therefore is limited in its ion formation. <span />
The correct answer is (B) Photosynthesis and diffusion from the air
Dissolved oxygen enters the water from photosynthesis and through air. The The aeration of water can be caused by wind. From the air oxygen diffuse into the water and gets mixed in the it through circulation. The oxygen is also produced as a waste product of photosynthesis from blue-green algae, phytoplankton, etc which is added in water.
When a stimulus is being detected, this stimulus is being sent to the brain through the sensory neuron, going to the spinal cord then to the brain. The brain then interprets these stimuli, and responds to it using the motor neurons. These are the neurons that are responsible in our actions depending on the stimuli we are exposed to. Hope this helps.
Triacy because it seems like a long word
If I'm correct the earth experiences a neap tide hope that helps:)