Atomic Structure Flashcards
Although the protons and neutrons are 2000 times more massive than the electrons, the nucleus only takes up a ….. Proportion of and atom
Tiny
Diameter of an atom
A tenth of a nanometer
The electrons orbit at relatively ….. Distances
Vast
The nucleus is only one 10 000th the size of the whole atom. Most of an atom is ….. Space
Empty
What are nucleons
Protons & neutrons
What is the proton number also known as
The atomic number
What defines the element
The proton number - no two elements will have the same number of protons
In a neutral atom. What two things are equal
The number of protons and electrons
What is the nucleon number (also known as mass number)
The total number of neutrons and protons
Isotopes have what
The same proton number but different nucleon number.
Different number of neutrons
Same number of protons
In general, the greater the number of neutrons compared with the number of protons, the ……. Unstable the nucleus
More
What may unstable nuclei be
Radioactive and decay to make themselves stable
What has the smallest relative mass
Electron
