Vocab Atoms Flashcards
Atom
the smallest unit of an element that maintains the properties of that element
Electron
a subatomic particle that has a negative charge
Nucleus
an atom’s central region which is made up of protons and neutrons
Electron cloud:
a region around the nucleus of an atom where electrons are likely to be found
Proton
a subatomic particle that has a positive charge and that is found in the nucleus of an atom
Atomic mass unit:
(amu) a unit of mass that describes the mass of an atom
Neutron
a subatomic particle that has no charge and that is found in the nucleus of an atom
Atomic number:
the number of protons in the nucleus of an atom (the number is the same for all atoms of an element)
Isotope:
an atom that has the same number of protons as other atoms of the same element but that has a different number of neutrons (resulting in a different atomic mass)
Atomic mass:
found by adding the number of protons and neutrons and expressed in atomic mass units
Four Forces in the Atom:
gravitational force, electromagnetic force, strong force, weak force
Gravitational force:
acts between all objects all of the time and depends on the masses of the objects and the distance between them (since atoms are very small, the gravitational force with atoms is small)
Electromagnetic force:
holds the electrons around the nucleus
Strong force:
holds the nucleus together (stronger than the electromagnetic force)
Weak force:
important force in radioactive atoms
Element
a substance that cannot be separated or broken down into simpler substances by chemical means
Periodic Table of the Elements:
arranges the chemical elements into rows and columns
Period
a horizontal row of elements in the periodic table
Group
a vertical column of elements in the periodic table (elements in the same group share chemical properties) Also called a family
