Q: Define Atom A) a small particle that is the building block of matter

B) two or more atoms that are held together by bonds and act as a unit anything that has mass and takes up space

C) a substance containing atoms of two or more different elements chemically bonded together

D) a substance that consists of only one type of atom

45 points how are people today being protected from tsunamis? earthquake data is analyzed to detemrine if a tsunami is likely, and if so, warnings are sent out. areas in tsunami risk zones are no longer heavily populated. radar is used to measure wave heights regularly. meteorologists study the winds to determine if wave heights will be large.