The element shown in the model is A. beryllium B. nitrogen C. fluorine D. neon

Building Blocks of the Universe

 In 1808, John Dalton proposed an explanation for the ‘magic’ of chemistry He reasoned that elements were composed of atoms & that only whole #’s of atoms can combine to form compounds He had 5 ideas about the nature of matter: 3 were right, 2 were a little off  In 1808, John Dalton proposed an explanation for the ‘magic’ of chemistry He reasoned that elements were composed of atoms & that only whole #’s of atoms can combine to form compounds He had 5 ideas about the nature of matter: 3 were right, 2 were a little off The Atom: From Alchemy to Science Sec 3-1 Pg 65-69

1.All matter is composed of extremely small particles called atoms 2.Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, & other properties ELEMENT 2 ELEMENT 2 ELEMENT 3 ELEMENT 3 ELEMENT 1 ELEMENT 1 ELEMENT 4 ELEMENT 4 Reality: Atoms of a given element all have the same number of PROTONS True

3.Atoms cannot be subdivided, created, or destroyed 4.Atoms of different elements combine in simple whole # ratios to form chemical compounds 5. In chemical changes, atoms are combined, separated, or rearranged False: atoms can be subdivided into smaller particles True

Dalton’s Atomic Theory of Matter has been modified. 1. All matter is composed of atoms 2. Atoms of any one element differ in properties from atoms of another element. All atoms of an element have the same number of protons, but they can have different masses. 3. Matter (atoms) cannot be created or destroyed. 4. Compounds are made of whole numbers of atoms. 5. Reactions rearrange how atoms are chemically bonded to one another. Dalton’s Atomic Theory of Matter has been modified. 1. All matter is composed of atoms 2. Atoms of any one element differ in properties from atoms of another element. All atoms of an element have the same number of protons, but they can have different masses. 3. Matter (atoms) cannot be created or destroyed. 4. Compounds are made of whole numbers of atoms. 5. Reactions rearrange how atoms are chemically bonded to one another. The Atom: From Magic to Science

The Atom!

 2 Areas of the atom:  Nucleus Protons Neutrons  Electron cloud

Electrons  Tiny, very light particles MASS= about 0  Have a negative electrical charge (-)  Move around the outside of the nucleus x kg 1/1837 of a proton

Protons  Much larger and heavier than electrons  Mass = 1.0 amu (atomic mass unit)  Protons have a positive charge (+)  Located in the nucleus of the atom

Neutrons  Large and heavy like protons  Mass = 1.0 amu  Neutrons have no electrical charge: NEUTRAL  Located in the nucleus of the atom

 All matter is composed of atoms.  The earth's crust is made up of 90 different types of atom.  Each unique type of atom is called an element.  Each atom contains a 3 types of subatomic particles with the following properties: Subatomic ParticleChargeMass Protonpositive1 atomic mass unit Neutronneutral1 atomic mass unit Electronnegative~0 mass units

P= 26 N= 30 P= 26 N= 27 They’re BOTH Iron Men – why?

Atomic number equals the number of ____________ Whole number of atomic mass equals the number of ______________ + ____________ The Atoms Family - Atomic Math Challenge Atomic Number Symbol Name Atomic Mass protons neutrons

 Please complete the table: ParticleLocationMassCharge Proton Neutron Electron nucleus1 amu + nucleus1 amu 0 electron cloud 0 -

Most of the atom’s mass. NUCLEUS ELECTRONS PROTONS NEUTRONS NEGATIVE CHARGE POSITIVE CHARGE NEUTRAL CHARGE ATOM QUARKS Atomic Number equals the # of... equal in a neutral atom

 QUARKS – basic particle and fundamental part of matter  6 types of Quarks: Top, Bottom, Charm, Strange, Up, Down…  Protons are made of 3 quarks: 2 up + 1 down  Neutrons are made of 3 quarks: 2 down + 1 ‘up’