What is Alchemy?
*Alchemy is a precursor of chemistry and speculative philosophy practiced in the Renaissance and Middle Ages
* It can be traced back to Ancient Egyptian and Ancient Chinese
Who helped develop the idea of an element
*Robert Boyle helped develop the idea of an element*Born in 1627 and died 1691
What is an Element?
* A substance is an element unless it can be broken down into simpler parts
* Matter can be broken down chemically into about 100 different elements
* 116 elements have been discovered only 88 elements are natural
* The name of the chemical elements have come from many sources
* Many of the names are derived from Latin and Greek
* Some of the names are created due to the way the element looks or from where is was found
What is a compound?
A compound is a distinct pure substance that is composed of the atom soy two or more elements and always contains exactly the same relative masses of those elements
What are parts of an atom?
*Proton
*Neutron
*Electron
What is an Isotope?
* For a given element the number of neutrons will vary
* Isotopes are atoms of the same element having difficult numbers of neutrons
* The nucleus of the hydrogen atom has a single proton
What is a mass number?
*The mass number of an element is approximately equal to number of protons plus the number of neutrons
Metals and Nonmetals
Metals
*Physical properties of metals
- efficient conduction of heat and electricity
- malleability
- ductility
- a lustrous appearance
Nonmetals
*Lacks properties of metals
*Nonmetals elements can be found in the gas, liquid, and solid
Positive and Negative charged electrons
* When the number of electrons change in an atom the charge of the atom changes
* If an atom gains an electron then the charge is negative
* If an atom loses an electron then the charge is positive
* An atom with a net charge is called an ion
Quizlets for Elements