Alexander's 1st power is the ability to have lasers. He is able to use lasers because arsenic is used in lasers to convert electricity into coherent light. The lasers help him stop the enemy. This is a chemical property.
Alexander's 2nd power is the ability to distract his enemy by forming a white cloud of arsenic trioxide. He creates this cloud when his body temperture rised. Arsenic trioxide is also very poisonous and can kill people very quickly. This is a chemical property.
One of Alexander's weaknesses is his bones are very brittle and he is easily hurt. This is a physical property.