Atomic & Mass Number Flashcards

All 5 cards in this deck

What is the atomic (proton) number of an atom?

The number of protons in its nucleus.

What is the mass (nucleon) number of an atom?

The total number of protons and neutrons in its nucleus.

What is the formula for the number of neutrons in a nucleus?

neutrons = mass number − atomic number

In the symbol ¹³₆C, what does each number tell you about the atom?

13 is the mass number and 6 is the atomic number, so the atom has 6 protons, 7 neutrons and 6 electrons.

True or false? The nucleus of each element has a characteristic positive charge.

True. Every atom of an element has the same number of protons (the atomic number), so its nucleus always has that same positive charge.