Structure of an Atom Flashcards
What is an atom made up of?
A nucleus that is surrounded by one or more electrons.
The nucleus is the…
very small center core of an atom.
What smaller particles is the nucleus made up of?
Protons and neutrons.
Protons have a…
POSITIVE charge.
Neutrons have…
no charge. NETURAL.
Electrons move…around the nucleus and have a…
Electrons move rapidly around the nucleus and have a NEGATIVE electric charge.
In an atom the number of…equals the number of electrons.
In an atom the number of protons equal the number of electrons.
An atom is…because the positive and negative electric charges are…
An atom is neutral because the positive and negative electric charges are balanced.
Electrons move around the nucleus in a… Scientists show this area as a cloud of..
Electrons move around the nucleus in a sphere-shaped area. Scientists show this area as a cloud of negative charge.
Electrons may be…
anywhere within the cloud.
Where do electrons with lower energy usually move?
Near the nucleus.
Where do electrons with higher energy usually move?
Farther from the nucleus.
Protons and neutrons are about…
equal in mass.
Electrons are much smaller than…It takes almost 2,000 electrons to equal the mass of one proton.
Electrons are much smaller than protons and neutrons.
Electrons take up much more space in the atom than the…
nucleus.
Atoms are so small their mass is measured in atomic mass units (….).
Atoms are so small their mass is measured in atomic mass units (amu).
A…has a mass about equal to one amu.
A proton or a neutron has a mass about equal to one amu.
