Chemistry Flashcards
Matter
A physical substance
Atom
Building blocks of matter
Element
Pure substance that cannot be separated into simpler substance by physical or chemical means
Molecules
two or more atoms joined together.
Same = element
different = compounds
Compounds
two different elements chemically bonded can only separated chemically
Mixture
two or more substances that are physically combined
John Dalton atom theory
He believed that elements were made up of atoms. Atoms cannot be divided or destroyed.
JJ Thompson atom theory
Suggested that electrons float in a blob of positive charge (plum pudding)
Rutherford atom theory
Atoms are mainly empty space
Some deflected meaning the nucleus was positively charged
Niel Bohr atom theory
believed that the electrons orbited the nucleus in shells
Describe reactivity of elements in the periodic table
Reactivity is increased when an element needs to lose or gain one or two electrons to have a full outer shell. The further away electrons are from the nucleus the weaker the connection is.
What is the difference between rust and corrosion
Corrosion is the result of a chemical reaction.
Rust is accelerated by certain chemicals
John Dalton periodic table development
Only 20 elements weren’t ordered a specific way
Johan Wolfgang Doblener periodic table development
Arranged in the increasing of atomic mass in triads
atomic weight of the middle element is equal to the average of the 2 end elements. 32 elements
John Newlands periodic table development
56 elements arranged in rows and columns by atomic weight
