Create an account
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?
Which is true?
A. Protons attract other protons.
B. Electrons determine the atom's size.
C. Most of an atom's volume is filled with matter.
D. Protons repel electrons.
Dr. Jones says an atom has 3 electrons in the first shell and four electrons in the second shell. Someone should tell Dr. Jones that ...
The first shell can only hold 2 electrons
Which statement is true of the energy levels of electrons in shells?
A. Electrons must lose energy to move from the first to the second shell.
B. The valence shell has higher energy than other occupied shells.
C. All the electrons in an atom have similar amounts of energy.
An atom has 6 electrons, 6 protons, and 6 neutrons. You can tell that this atom belongs to the element _____ because _____________________.
C; it has 6 protons.
An atom has 8 protons, 8 neutrons, and 8 electrons. Another isotope of the same element might have ...
A different number of neutrons but the same number of protons
Which statement is most useful in explaining why chemists assign atoms to chemical elements by counting protons?
A. The nucleus doesn't change in stable isotopes.
B. The proton's negative charge holds electrons in the atom.
C. Protons at the atom's surface determine the atom's behavior.
D. 99% of the atom's mass consists of protons.
E. None of these. Elements are defined by the number of proton
Consider a hypothetical atom with an atomic number of 4 and a net electronic charge of +1. How many neutrons does this atom have?
The answer cannot be determined by that information. Correct
All the atoms of an element have the same number of protons, but some atoms have more neutrons than other atoms of the same element and therefore have more mass. Without the mass number (number of protons + neutrons), it is not possible to determine the number of neutrons.
A nitrogen isotope has an atomic number of 7 and an atomic mass of 15. The respective numbers of neutrons, protons, and electrons it has are _____.
8, 7, 7
Please allow access to your computer’s microphone to use Voice Recording.
Having trouble? Click here for help.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!Reload
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Please upgrade Flash or install Chrome
to use Voice Recording.
For more help, see our troubleshooting page.
Your microphone is muted
For help fixing this issue, see this FAQ.
Star this term
You can study starred terms together