Presentation on theme: "The Structure of the Atom. Inside the Atom Atoms are made of subatomic particles. Protons Neutrons Electrons Protons and neutrons are in the."— Presentation transcript:
Inside the Atom Atoms are made of subatomic particles. Protons Neutrons Electrons Protons and neutrons are in the nucleus. Electrons are found surrounding the nucleus.
Protons & neutrons Contribute to most of the mass of the atom. Each is 1840 times the mass of electrons. Neutrons have no charge Neutrons and protons are attracted through “strong force” attractions. Protons have a positive charge
The # of protons in the nucleus of an atom is the atomic number. Atomic number identifies the atom as a particular element
EG. # of protons? 66 Atomic number? 66 element? Carbon It will always be carbon! Cannot change.
If a proton is somehow removed or added, it will no longer be carbon! The sum of protons and neutrons is the mass number. Mass # is a whole number, so you will have to round the # found on the periodic table. EG. Carbon: 12.011 Mass = 12 Proton = 6 Neutron = ? 12 - 6 = 6
The symbols that we use to represent different chemicals are the same in each language, although we do call elements different names. We use a standard atomic notation to represent elements. Mass # is written above, atomic # below and the symbol in large letters to the left.
TRY THIS! On page 189 of your textbook, do activity 5-4.
Bohr-Rutherford models A way of representing the atomic structure of an element. Electrons occupy specific energy levels called shells. Electron that are further away from the nucleus have more energy. You have to fill the shell closest to the nucleus first. The first shell can only take 2 electrons, the next one can take 8, the 3rd can take 8 also.
How to Draw it? 1. Draw a circle (nucleus) and write the # of protons of that atom next to a “p”. And the number of neutrons next to an “n”. EG Boron Proton # = ? Neutron # = ? 5p 6n
Step 2: determine the # of electrons in the atom (same as proton #) Draw the energy levels. 5p 6n Electrons: 5
Step 3: Starting with the closest energy level to the nucleus, put in a max of 2 electrons. Second level can take a max of 8 electrons Third level can also take a max of 8. For boron, we only need two levels. 5p 6n
YOU TRY IT!! Fill in the Bohr- Rutherford diagrams for the first 20 elements.
Isotopes One of two or more forms of an element that have the same number of protons but a different number of neutrons. Since each isotope has a unique mass number, you can specify an isotope of an element by placing its mass number after the name of the element. EG. Hygrogen-1 and hydrogen-2 Try this: p. 193 #1-8