Matter And Atomic Theory Flashcards
All things are made of…
Matter
What is matter?
We don’t really know for sure.
What were the elements discovered by Greek philosophers?
earth,water,fire,air
Democritus of Greece proposed that…
Matter could be cut up into smaller and smaller pieces, the smallest piece was called “atoma”
What was the particle theory of the 16th century?
.All matter is made of very small particles
.there is space between the particles
.Each pure substance has its own unique kind of particles
.particles are attracted to each other and are always moving
.particles at a higher temperature move faster
What is John Dalton’s atomic theory?
.All matter is made up of small particles called atoms
.Atoms can’t be created destroyed or divided into smaller particles
.All atoms of the same element have the same mass and size
.Atoms of one element are different in mass and size than other ones
.compounds are created when atoms of different elements link together
What is a element?
A pure substance made of one type of atom. Each element has its own distinct properties and cannot be broken down into a simpler substance.
What is a compound?
A pure substance that is made up of two or more elements that have been chemically combined together. Compounds can be broken down into elements by chemical means.
What did J.J Thompson add to the Atomic theory?
He discovered the electron.
What is a electron?
A electron is a sub-atomic particle with a negative charge.
What did Ernest Rutherford add to the atomic theory?
.Discovered the atomic nucleus, which is the center part of an atom
.protons and neutrons make up most of the mass.
.the atom is mostly empty space
. He came up with the planetary model
What is a proton?
A positively charged sub-atomic particle found in the nucleus.
What did James Chadwick add to the atomic theory?
He discovered the neutron
What is a neutron?
An uncharged particle of similar size and mass to the proton.
What did Neil’s Bohr add to the atomic theory
Electrons are in fixed orbits with definite energies called electron shells.
Each shell can only hold so many electrons
