What Is An Atom?
atoms all matter is made of elements substances that cannot be broken down by chemical activity an atom is the smallest particle of an element that retains the elements properties atoms are the building blocks for everything in the universe including ourselves people often think of atoms as the smallest possible forms of matter but even smaller particles make up atoms each atom has a dense Center called a nucleus the nucleus contains neutrons which have a neutral electric charge and protons which are positively charged the number of protons in an atom determines an elements physical properties no two elements have the same number of protons revolving around the nucleus like planets around the Sun are negatively charged particles called electrons electrons and protons attract each other so atoms usually have equal numbers of the two particles scientists assign atoms and atomic number and atomic mass unit the atomic number is the number of protons present in the atom for inst...