At the center of an atom lies the NUCLEUS, containing PROTONS and NEUTRONS.
ELECTRONS orbit around the nucleus in electron shells.
A) shells
B) nucleus
C) electrons
Atoms are the smallest part of an element that can exist.
Incredibly small and makes up everything in the universe
Composed of sub-atomic particles: protons, neutrons and electrons
Atoms are neutral and no overall charge for they have the same number of protons and electrons cancelling each other out.
Sub-atomic particles' properties:
A) positive
B) neutral
C) negative
D) 1
E) 1
F) very small
Relative Atomic Mass (RAM or Ar)
the measure of the averagemass of an atom.
The NUCLEUS is about 1/10,000th of the atom's total size, but it holds nearly ALL the atom's mass:
Radius of an ATOM: 0.1nm (1 x 10-10 m)
Radius of a NUCLEUS: 1 x 10-14 m
Atoms of each element is represented by a CHEMICAL SYMBOL which can be found in the PERIODIC TABLE.
E.g. Carbon has the symbol C.
A) mass number
B) chemical symbol
C) atomic number
Element
A substance made up of onetype of atom.
When atoms have different numbers of PROTONS, they're classified as DIFFERENT elements, this means the ATOMIC NUMBER determines the ELEMENT of an atom.
To find the number of NEUTRONS, SUBTRACT the atomic number from the mass number:
ISOTOPES are different forms of the same element, having the SAME NUMBER OF PROTONS but DIFFERENT NUMBERS OF NEUTRONS.
Compounds are substances that form when two or more elements react and their atoms chemically combine in fixed ratio by mass.
In compounds, only the ELECTRONS are involved in bond formation while the nuclei remain unchanged.
PROPERTIES of a compound are usually different from the original elements.
FORMULAS
represents compounds and show the elements and the number of atoms of each element in a compound.
Formulation
A mixture that has been designed as a useful product including: