What is an atom? The Basic Building Block of matter.
What are the three parts that it is made of? Protons Neutrons Electrons
What are Protons? Positively Charged Particles Found in the nucleus of an atom. They are about the same mass as a neutron.
What are neutrons? Neutral particles or parts of an atom with NO CHARGE. They are found in the nucleus of an atom. A neutron is about the same mass as a proton.
What are electrons? Negatively charged particles They are found floating around the nucleus. Electrons are very small Protons are about 1,836 times more mass than an electron.
What is an element? A type of atom with a specific number of PROTONS.
What is the periodic table of elements? The periodic table is a table that tells us the atomic number, the atomic mass and the chemical symbol of an element. It shows trends in properties of the elemental groups.
Atomic theory according to Dalton All elements are composed of atoms that cannot be divided. All atoms of the same element are exactly alike and have the same mass. Atoms of different elements have different masses.
Atomic theory according to Dalton Atoms of one element cannot be changed into atoms of a different element. Every compound is composed of atoms of different elements, combined in a specific ratio.
Advancements Thomson- Postive and negative charges of atom. Rutherford- The Nucleus contains protons. Bohr- Electrons have a certain quantity of energy.
Advancements Cloud model- Electrons don’t circle the nucleus like planets, they are in cloud like regions. Chadwick – He discovered neutrons in the nucleus.
Modern atomic theory At the center of an atom there is a tiny massive nucleus containing protons and neutrons. Surrounding the nucleus is a cloudlike region of moving electrons.
Number of protons neutrons and electrons Atomic number = the number of protons Atomic mass = the number of protons and neutrons The number of electrons is equal to the number of protons.
Isotopes Isotope= atoms of the same element that have a different number of neutrons. Remember, the number of protons is always the same.
Periodic table of elements The periodic table is an arrangement of elements showing the repeating pattern of their properties. The periodic table can be used as a tool to predict the properties of an element.