What is Chemistry
Study of matter and its changes
What is Matter?
Anything that has mass and occupies space
What are Atoms?
Building block of matter.
Made of Protons, Neutrons, and Electrons
Atomic # = # of Protons
Atoms/groups of atoms bonded together with a net charge
What are compounds
More than one kind of atom in a fixed ratio by mass
Groups of atoms bonded together by covalent bonds
Has both + and - charged ions
Attracted by charge and are not molecules
No change in chemical makeup
EX: melting ice
Always makes a chemically different substance
Ex: 2H2O --> 2H2 + O2
When you look at it and say what it is
Extensive: Size (Volume)
What are substances?
Pure materials that can't be physically separated into simpler components
Chemical and Physical properties are uniform
Compound or Element
2 or More Pure Substaances
- Can separate mixture into simpler substances
Uniform in physical and chemical properties
EX: Normal saline
Distinct phase boundaries where chemical and/or physical properties change
Where are protons and neutrons located?
Where are electrons located
Around the nucleus in cloud-like orbitals
What has wave-like properties rather than geometric properties?
All atoms have neutrons except for ?
What determines the atom's identity?
The Atomic Number = # of Protons
How do you get the Mass Number?
Neutrons + Atomic Number
What are isotopes?
Same Atomic Number, Different Mass Number
(diff # of neutrons)
What is Periodic Law
Properties of elements are periodic fxns of their atomic #
On periodic table, what are the verticle columns?
Have similar chemical and physical properties
On the Periodic table, what are the rows
Adding e- to energy levels, e- shells
Element at the end of a period has a full e- shell
Nearly full e- shell --> accepts e-
Nearly empty e- shell --> release e-
Mostly on Left Side
Shiny, Ductile, Malleable, Good electric conductors
React to form Cations