Chapter 17 Section 1

Shorthand Chemical Symbol: The shorthand way to write the name for an element Symbols are written three ways: 1 capital letter 1 capital letter and one small letter 1 capital letter and two small letters

Shorthand How were the chemical symbols picked? 1st letter of the elements name 1st letter of its name and another letter from its name Some are derived from Latin Some honor scientists, places, or the elements properties

Shorthand Examples O = Na = Hg = Au = Al = Ca =

Atomic Components How many atoms is an element made of? Atom: 1 type of atom Atom: Smallest piece of matter that still retains the properties of the element

Atomic Components What are the subatomic particles that make up an atom? Proton Neutron Electron Where can we find protons and neutrons? In the nucleus

Atomic Components What are the charges for the subatomic particles? Protons Positive Neutrons Neutral Electrons Negative

Quarks Are electrons composed of smaller particles? No Are protons and neutrons make up of smaller particles? Yes What are they called? Quarks

Quarks Currently there are six different quarks Scientists hypothesize that three quarks held together with strong nuclear force makes a proton Another arrangement with three quarks makes a neutron

6th Quark It took nearly 450 scientists over several years to find the 6th quark Only one billionth of a percent of the proton collisions showed the presence of the sixth quark Referred to as the top quark

Finding Quarks Scientists accelerate charged particles to very fast speeds Force them to collide with protons This causes them to break apart They can then examine the particles that result from the collision

Changing Atomic Model Did we always know that there were atoms? It was originally thought that matter was uniform throughout and not composed of smaller particles In the 1800s Dalton found proof that atoms exist

Electron Cloud 1926 the electron cloud model was developed Area around the nucleus of an atom where its electrons are most likely found It is impossible to describe the exact location of an electron in the cloud