2.1 — atomic structure Flashcards
what are the three fundamental subatomic particles present in an atom?
electrons, protons and neutrons
what is the collective name for protons and neutrons?
nucleons
where are nucleons located?
in the atom’s nucleus
what part of an atom is small and dense, containing the majority of its mass?
the nucleus
where are the electrons located?
in shells/orbitals orbiting the nucleus
what is the charge of a proton?
positive
what is the charge of a neutron?
no charge/neutral
what is the charge of an electron?
negative
although electrons occupy a _____ region of space, most of an atom’s volume is actually _____ _____. what are the missing terms?
large/empty space
how are the properties of subatomic particles expressed and why?
relative mass and charge are used to express the properties of subatomic particles as the true values are extremely small
what are the relative masses of the subatomic particles?
proton — 1
neutron — 1
electron — 0.0005 or 1/2000
what are the relative charges of the subatomic particles?
proton — +1
neutron — 0
electron — -1
what do nuclear symbols provide?
a concise way to represent the composition of an atom
what is mass number?
the total number of nucleons (protons and neutrons) in the nucleus
what is the atomic number?
the number of protons in the nucleus, which uniquely identifies the element.
what is the symbol of mass number?
A
what is the symbol for atomic number?
Z
how do you determine the number of protons in an atom?
the number of protons is equal to the atomic number (Z)
how do you determine the number of neutrons in an atom?
the number of neutrons is calculated by subtracting the atomic number (Z) from the mass number (A)
how do you determine the number of electrons in a neutral atom?
in a neutral atom, the number of electrons is equal to the proton/atomic number (Z)
what are ions?
ions are atoms that have gained or lost electrons, resulting in an overall positive or negative charge
what are anions?
anions are negative ions — atoms with more electrons than protons, causing an overall negative charge
what are cations?
cations are positive ions — atoms with fewer electrons than protons, causing an overall positive charge
how do you determine the number of electrons in an ion?
the number of electrons in an ion is calculated by subtracting the ion’s charge from the proton/atomic number (Z)
