Atoms, Ions, and Compounds Flashcards
What are electrons arranged in around the nucleus?
Shells
How do chemists compare the masses of subatomic particles?
Using relative masses
Which two subatomic particles have virtually the same mass?
Protons and neutrons
What are the charges of the three subatomic particles?
Protons - positive
Electrons - negative
Neutrons - no charge
Where is nearly all of an atoms mass?
In the nucleus
What is the relative mass of an electron?
1/1836
What is the overall charge of an atom?
Zero - the total positive charge of the protons is cancelled out by the total negative charge of the electrons
What is needed as the nucleus gets larger?
More neutrons to hold it together
What identifies the element?
The number of protons
What does every atoms of the same element contain?
The same number of protons
What is an atomic number?
The number of protons in that element
What are isotopes?
Atoms of the same element with different numbers of neutrons and different masses
What are most elements made up of?
A mixture of isotopes
What do chemical reactions involve?
The electrons surrounding the nucleus
What is similar about isotopes of the same element?
Same number of protons
Same number of electrons
What is an ion?
A charged atom
What is a cation?
A positive ion
- atoms with fewer electrons than protons
What is an anion?
Negative ion
- atoms with more electrons than protons
What is 1 u?
Standard mass for atomic mass
- 1/12th mass of a carbon 12 atom
What is relative isotopic mass?
Mass of an isotope relative to 1/12th mass of a carbon 12 atom
What is relative atomic mass?
The weighted mean mass of an atom of an element relative to 1/12th the mass of an atom of carbon 12
How are the percentage abundance a of isotopes in an element sample found?
Mass spectrometer
What is a binary compound?
A compound containing only two elements
What are poly atomic ions?
An ion containing atoms of more than one element bonded together
