Physics. Ch. 11
What is meant by the term nucleon?
A proton or neutron
As the text cites, atoms are incredibly tiny, numerous, perpetually moving, and what else?
Ageless
Why can't atoms be seen with a powerful optical microscope?
Atoms are much smaller than a wavelength of light.
What is a compound? Cite two examples.
Atoms of different elements with bonds between them: NaCl and H2O
What is a mixture? Cite two examples.
Atoms pressed together without bonding: air and salt and sand
What are the five most common elements in humans?
C, H, O, N, and Ca
What kind of attraction pulls electrons close to the atomic nucleus?
Electric
Since atoms are mostly empty space, why don't we fall through a floor we stand on?
Electrons in one atom repel the electrons in another.
What is the most abundant element in the known universe?
Hydrogen
Which of the following is an element?
Hydrogen
How does one isotope differ from another?
It has a different number of neutrons.
How does the electric charge of a proton compare with the electric charge of an electron?
It is equal and opposite.
How are most of the elements with nuclei heavier than those of hydrogen and helium formed?
Nuclear fusion in stars
What does the atomic number of an element tell you about the element?
The number of protons in its nucleus
Why can atoms be seen with an electron beam?
The wavelength of the electrons is smaller than an atom.
An important feature of atoms is that they __________.
have wave properties
