The Atom is made up of three particles -neutrons -electrons -protons The neutrons are neutral, protons are positive, and electrons are negative. The protons and neutrons live inside of the nucleus. The electrons are on the outside of the nucleus.
Atomic mass is number of neutrons and protons in the atomic nucleus. It is different from the atomic number because whereas atomic mass counts nucleons, atomic number counts the protons within the nucleus.
An element is a pure chemical substance that is made up of one specific atom. They can be distinguished by the atomic number. Atomic number is the number of protons within a nucleus. Every element is different, but there can be variations of the elements and they are known as isotopes. They have the same number of protons, but the amount of neutrons differ. For example carbon-13, carbon-14, and carbon-15 are isotopic variations for carbon. Respectively, their mass numbers (13, 14, 15) are what make all three carbons different even though there are not three different carbons on the Periodic Table.
Atomic Structure 101 Atoms are made up of electrons (negative), neutrons (neutral), and protons (positive). Electrons surround the nucleus, which is made up on neutrons and protons. Atomic mass is the number of protons and neutrons in an atoms, and atomic number is the number of protons singularly. An isotope is a variation of an element, such as carbon-13.
Below is an example of how to calculate the average atomic weight of an element in the Periodic Table. Which I chose Carbon. Each exact atomic weight is multiplied by its percent abundance (expressed as a decimal). Then, add the results together and round off to an appropriate number of significant figures.
Isotope Isotopes are variants of a particular chemical element such that, while all isotopes of a given element share the same number of protons in each atom, they differ in neutron numbers.
Scientists behind the Atomic Structure Newton- England 1704 Newtons significance to the history of the atomic structure of an atom is he began the theory and to understand that all atoms or particles move and are not stationary.
Dalton- England 1803 John Dalton is the man responsible for creating Dalton's Theory.
matter is composed of extremely small particles called atoms
atoms are indivisible and can't be destroyed
atoms of a given element are identical in size, mass, and chemical properties
atoms of specific elements are different than that of those of other elements
in a chemical reaction, atoms separate, combine and/or rearrange
Rutherford-USA 1911 Ernest Rutherford was the man in the early 20th Century was the gold foil experiment. He shot Alpha Atoms through an extremely thin piece of gold foil, to see where on the surrounding wall it hit. He thought they would all go straight through, but that wasn't the case. A small amount went off to the side or towards the back. This then meant that there was something in the center of the atoms, which is the nucleus. This is where the nuclear model of an atom comes from.