Dead zones are not limited to occurring near the equator, as they are mostly naturally occurring and do not have a single cause. However, human activity has also begun to create dead zones around the world. Furthermore, most countries near the equator are not as industrial, or do not have as much negative human activity as those further from the equator, so it is less likely for dead zones (the non-natural type) to occur there.
Carbon atoms have four electrons in their outer shell. So, it exhibits tetravalency & thus, a single carbon atom can form a maximum of four (4) bonds with other atoms
