Atomic Number and Mass Number

Question	Answer
Atomic number is used to identify what element an atom belong to	Each element has a unique atomic number
The atomic number is the number of protons in the nucleus	The symbol for the atomic number is 'Z'
The mass number of an atom is the number of protons + neutrons	The symbol for the mass number is 'A'
If atoms have the same atomic number but different mass number they are...	Isotopes
Isotopes were first suggested by Frederick Shoddy in 1913	Carbon 14 is an isotope used in dating artifacts
The periodic table is a list of all known elements ordered by atomic number	Dmitri Mendeleev ordered the first periodic table by atomic number
The modern periodic table contains 118 elements	New elements are still being discovered!

Resource summary

	Created by PatrickNoonan about 11 years ago