The Amazing Atom Atoms l All matter is

The Amazing Atom

Atoms l All matter is made of very tiny particles l. These atoms have the same properties as larger particles of the matter have

Parts of the Atom l Subatomic Particles – smaller than an atom (parts) l. Proton l. Neutron l. Electron

Subatomic Particles l Protons + (p ) l. Positive charge l. Each one has a charge of +1 l. Located in the nucleus l. Each one has a mass of 1 amu (atomic mass unit)

Subatomic Particles l Neutrons l. No 0 (n ) charge l. Located in the nucleus l. Each one has a mass of 1 amu (atomic mass unit)

Subatomic Particles l Electrons (e ) l. Negative charge l. Each one has a charge of -1 l. Located in the space (cloud) around the nucleus l. Each one has a mass of about 0. 0006 amu (atomic mass unit)

The Atom l The nucleus has p+ and n 0 l. Positively charged l The electron cloud has el. Negatively charged l The number of protons equals the number of electrons in a neutral atom

Periodic Table l The periodic table gives us lots of information about the elements. 1 Atomic Number H Element Symbol Hydrogen Element Name 1. 008 Average Atomic Mass

Symbol Practice For the element name, give the symbol. Helium Carbon Sulfur Oxygen Magnesium

Element Practice For the symbol, give the element name. Li N Ar Al Na

Atomic Number l Atoms of different elements are different l The number of protons in the nucleus is the atomic number of an element

Atomic Number l The atomic number identifies the element l Like DNA for an element

Proton Practice: How many protons are in each of the following elements? Carbon Potassium Nitrogen Calcium Silicon

Electrons l Electrons give atoms their chemical properties l In order for an atom to have a neutral charge, it must have the same number of electrons as it has protons. l Electrons = protons = atomic number

Electron Practice: How many electrons are in each of the following elements? Helium Chlorine Nitrogen Aluminum Boron

Mass Number l All atoms have a mass number l We can figure it out by rounding the Average Atomic Mass to the nearest whole number l Mass number = protons + neutrons l Neutrons = Mass number – protons

Finding Neutrons l Example: Carbon l Round the Average Atomic Mass to the nearest whole number: 12. 01 rounds to 12 l How many protons in carbon? 6 l Neutrons = Mass number – protons Neutrons = 12 – 6 = 6

Neutron Practice: How many neutrons are in each of the following elements? Oxygen Chlorine Argon Aluminum Phosphorus

l Atomic Structure Practice l First 25 Elements Activity

Isotopes l Isotopes of an element have the same number of protons, but different numbers of neutrons. l There can be many isotopes of the same element.

Atom Concept Map

Isotopes l The average atomic mass of an element is determined by taking a weighted average of all of the isotopes of an element.

Isotope Symbols l Isotopes of elements have symbols called isotopic symbols: X = Element symbol A = Mass number Z = Atomic number

Isotope Symbols l The isotope symbol for carbon would be: X = Element symbol = C A = Mass number = 12 Z = Atomic number = 6

Isotopes of Candium Activity

Quick Check What is the atomic number of antimony? l What is the symbol for tungsten? l How many protons are in tin? l How many electrons are in potassium? l How many neutrons are in phosphorus? l What is the mass number of lead? l

Isotopic Symbol Practice

The Bohr Model of the Atom l Bohr developed the “planetary” model of the atom, with electrons in orbits around the nucleus. l Each of these “orbits”, which we now call shells, is an energy level for electrons. l We start by filling the shell closest to the nucleus first

The Bohr Model of the Atom l Each of the shells can only hold a certain number of electrons l 1 st shell – maximum 2 electrons l 2 nd shell – maximum 8 electrons l 3 rd shell – maximum 18 electrons l Additional shells can hold more, but we do not have to go past the 3 rd shell

The Bohr Model of the Atom l Let’s see what that looks like for hydrogen: How many protons? How many electrons? How many neutrons?

The Bohr Model of the Atom l Let’s see what that looks like for lithium: l Build a Bohr Diagram

Bohr Model Practice l Please do only the following elements on your Bohr Model Worksheet: Sodium Hydrogen Carbon Silicon Oxygen Chlorine Argon Magnesium

Human Bohr Model l Human Bohr Model. avi