Chapter 1: Atomic Structure Flashcards
What is the charge of a proton?
+1e
What is one atomic mass unit (amu)?
the approximate mass of one proton
What is the atomic number (Z)?
number of protons in an atom
How are elements identified/differentiated?
by their unique atomic number (the number of protons an atom of that element contains)
What do each of the numbers represent?
What is a neutrons charge?
zero / no charge
How does a neutrons mass compare to that of a proton?
the mass is slightly larger than that of a proton
The mass of an atom is made up almost entirely by the mass of _______.
the protons and neutrons within the nucleus
What is the mass number (A)?
the sum of protons and neutrons
can vary within atoms of the same element
Atomic weight
the weighted average of all isotopes of an element
What are isotopes?
atoms of the same element with:
- same atomic number (protons)
- different mass number (neutrons)
What doe the numbers represent in the following convention:
mass number = # protons + # neutrons
atomic number = # protons
What are the numbers of protons and neutrons in these 3 carbon isotopes:
Define electrons.
electrons move through the space surrounding the nucleus and are associated with varying levels of energy
What is the charge of an electron?
– 1 e
How does the mass of an electron compare to that of a proton?
that mass is approximately 1/2000 that of a proton
What are energy levels of an electron?
an electrons energy level describes the distance at which an electron moves around the nucleus
An electron closer to the nucleus will have a _______ energy level than one further from the nucleus.
lower
Electrons further from the nucleus are called:
valence electrons
What are 3 characteristics of valence electrons.
- most likely to become involved in bonds with other atoms because they experience the least electrostatic pull from their own nucleus
- determine the reactivity of an atom
How does an atom become charged?
atoms can share or transfer their valence electrons to bonds allow the atom to increase its stability
Cation vs anion?
Cation: positively charged atom
Anion: negatively charged atom
Heisenerg uncertainty principle
we cannot know both the position and speed of a particle, (ex. electron) with perfect accuracy
the more we nail down the particle’s position, the less we know about its speed and vice versa
Hund’s Rule
each orbital in a sublevel will receive 1 electron before any orbital receives 2
Pauli Exclusion principle
1) no more than two electrons can occupy the same orbital
2) two electrons in the same orbital must have opposite spins
principle quantum number
refers to the size and energy level of the orbital an electron is placed in
azimuthal quantum number
3D shape of the orbital
magnetic quantum number
orbital orientation
ms quantum number
electron spin direction
free radical
an atom or molecule with an unpaired electron
