I believe the answer is A chromosome
Answer:
In the middle of every atom is the nucleus. The nucleus contains two types of subatomic particles, protons and neutrons. The protons have a positive electrical charge and the neutrons have no electrical charge. A third type of subatomic particle, electrons, move around the nucleus
All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons.
Sodium chloride because it contains the most reactive metal(sodium) and most reactive non-metal(chlorine).
Do you need help with something?