Chapter 2: Atomic Structure Flashcards
What is important about the nucleus of an atom?
most mass of an atom and all its positive charge resides in the nucleus
What is most of an atom?
empty space, with electrons moving around the nucleus
what do electrons, protons, and neutrons do?
influence chemical behavior
What are the charges of protons, electrons, and neutrons?
Proton: 1 +
Electron: 1 -
Neutron: uncharged
Which two subatomic particles are held by the strong nuclear force?
protons and neutrons
How many protons and electrons are in an atom?
the same number of protons and electrons, no net charge
What are electrons attracted to?
protons in the nucleus
What is the mass number?
number of protons + number of neutrons
What is the atomic number?
number of protons in an atom
What is significant about the atomic number of an element in relation to its number of electrons?
because atom’s are electrically neutral, the # of protons = the # of electrons
What are isotopes?
atoms of a given element with a different number of neutrons; same atomic number, different mass number
What are atomic mass units?
Convenient ways to express the mass of atoms.
What is atomic weight?
Average atomic mass
(isotope mass x fractional isotope abundance)
expressed in amu
