Atomic Structure
Which of the following groups of subatomic particles are comparable in size and mass?
proton and neutron
what is all matter made of?
atoms
the radius of an atom is closest in size to a ______.
nanometer
The ______ is a small, dense, positively-charged region at the center of the atom.
nucleus
What do all atoms of the same element have in common?
number of protons
Overall, the nucleus of an atom has a(n) _____ charge.
positive
Which of the following are features of the nucleus of an atom?
-The nucleus has a tiny size relative to the total space occupied by the atom. -The nucleus is located at the center of the atom. -It has relatively great mass compared to the other components of the atom. -The nucleus contains protons and neutrons.
Subatomic particles that do not possess any charge but provide mass to atoms are called _____.
Neutrons
what is contained in the nucleus of an atom?
Protons and neutrons
Where are the subatomic particles located?
The protons and neutrons are found inside the nucleus, and the electrons are found on the valence shells
An _____ is the smallest particle of an element that has the element's properties.
atom
the density of nuclear matter:
does not change with the atomic numbers
Which of the following subatomic particles orbits the nucleus?
electron
which of the following are not located in the nucleus of an atom
electron
Particles that "orbit" the center of an atom are called
electrons
Atoms of helium or nickel would represent _____. These are pure substances that can not be broken down into simpler materials or particles.
elements
Because protons and neutrons make up the nucleus, and protons have a positive charge, neutrons have a negative charge.
false
Electrons are significantly smaller than protons and neutrons, we can ignore electrons when we consider the physical property of an atom.
false
Only a million atoms would fit inside the period at the end of this sentence.
false
The strong nuclear force holds together the electrons and the neutrons while electrical charges push the electrons away from each other.
false
There is an electric force of repulsion between neutrons and protons.
false
the nucleus makes up about 1/100th of the total radius of an atom
false
the nucleus of all atoms must consist of protons and neutrons
false
the small, dense region at the center of an atom is the _____.
nucleus
A neutral atom has equal numbers of ____ and electrons.
protons
Subatomic particles with a positive charge are known as _____.
protons
Which describes the density of the atomic nucleus compared to the density of the entire atom?
the density of the nucleus is very much larger than that of the atom
All atoms of the same element have the same number of protons.
true
An atom containing an equal number of protons and electrons is electrically neutral.
true
In a neutral atom, the number of protons is equal to the number of electrons.
true
The nucleus is very dense because it has virtually all of the atom's mass, but just a tiny fraction of the atom's total size.
true
The nucleus of an atom consists of protons and neutrons bound by a strong nuclear force.
true
the nucleus of the atom is a positively charged region at the center of an atom, which consists of protons and neutrons
true
there is an electrical force of repulsion between protons in the nucleus
true
