Presentation on theme: "ATOMS Basic building blocks of all matter."— Presentation transcript:
1 ATOMS Basic building blocks of all matter. Matter – everything that has mass.The smallest particles into which an element can be divided and still be the same substance.
2 Atomic StructureProtons – positively charged particles inside the nucleus.Neutrons – neutral particles inside the nucleus that have No charge.Electrons – negatively charged particles in atoms found around the nucleus.
3 Atomic Mass Unit (amu)Unit of measurement for the mass of subatomic particles.1 amu = 1.7 X They are TINY!!!gramsProton = 1 amuNeutrons = 1 amuElectrons = almost zero (TINIEST particle with the least mass)Most mass is in the nucleus with protons and neutronsOtherwise atoms are mostly EMPTY SPACE
4 Atomic Number The number of protons inside the nucleus of the atom. Determines the element.All atoms of an element have the same atomic number.Atoms have no charge because the # of protons (+ charge) is = to the # of electrons (- charge).
5 IsotopesAtoms of elements that have the same number of protons (atomic number) but a different number of neutrons inside the nucleus.
6 Mass NumberThe total number of protons and neutrons in an atoms nucleus.Protons + Neutrons = Mass Number
7 Atomic MassThe weighted average of the masses of all the naturally occurring isotopes of an element.Average of Protons + Neutrons of all an elements Isotopes = Atomic Mass
8 ELEMENTS Are atoms Identified by it’s atomic # (# of protons) Arrangement of electrons determines the elements properties such as conductivity and reactivity.
9 Energy Levels - Electron Clouds Regions around the nucleus where electrons are arranged.Electrons further away from the nucleus have more and more energy.Each level or cloud can hold a specific # of electrons.1st level - 2 electrons2nd level - up to 8 electrons
10 Valence ElectronsThe electrons in the outermost energy level (electron cloud).Very important because they determine how an element will react with other substances