(Q1) Atoms, Electron Configuration pg 21-31 Flashcards
Atom
The smallest particle of an element
- has the same number of protons and electrons
What are atoms composed of?
Positively charged nucleus surrounded by one or more negatively charged electrons
What does the nucleus contain?
Protons and Neutrons
Proton
- positively charged
- every element has at least one
- determines the total positive charge of on the nucleus
- 1 amu
Neutron
- No charge
- 1 amu
- atomic mass - atomic number
Nucleus
The positively charged central region of an atom, composed of protons and neutrons and containing almost all the mass of the atom
Isotopes
Atoms of the same atomic number and different masses
-  We’ll have the same number of protons and electrons but will have a different number of neutrons
Valence Electrons
- the electrons in the outer most energy level
- Determine the chemical properties of the atom/what the element will react to
- atoms with the same number of valence electrons often have similar chemical and physical properties
Electron Configuration
Shorthand system to symbolize positions of electrons in atoms
- eight valence electrons = stable (noble/inert gases)
- elements with less than eight valence react with other elements to achieve a stable electron configuration
Orbitals
Plots the estimate where elements are found in energy levels
- Each orbital represents a probability of finding an electron at a given distance from the nucleus
What types of orbitals are there?
1 s orbital
3 p orbitals
d,f
- Each orbital can hold only two electrons, going to instability caused by repulsions of negative charges
What pieces of information does the electron configuration give?
- The number of the energy level
- the type of orbital
- how many electrons are in the orbital
Ion
An atom or molecule in which the total number of electrons is not equal to the total number of protons
- Gives the atom a net positive or negative electrical charge
Group IA Elements
Alkali metals
- have one electron in their outer shell (1 valence electron)
- charge of +1
Group IIA Elements
Alkaline Earth Metals
- Two valence electrons,
- can easily lose its valence electrons
- +2 charge
Group VIIA elements
- Halogens
- have seven valence electrons
- Tend to gain one electron
- -1 charge
Group VIIIA Elements
- Noble Gases
- 8 valence electrons
- Tend not to react with other elements because they have a stable electron configuration
Covalent Bonding
- Results from electron sharing
- atoms tend to share electrons to achieve a stable electron configuration
- covalent = share 1 pair of electrons
- double covalent= share 2 pairs
- triple covalent= share 3 pairs
Polar Covalent Bond
covalent bond in which the atoms have an unequal attraction for electrons, and so the sharing is unequal.
Nonpolar Bond
electrons are shared equally between two (same) atoms.
