Posts Tagged ‘atomic structure’

Lewis structures and bonding

Tuesday, February 15th, 2011

Carbon dioxide octet dot cross from wikimedia commons

As a good introduction to bonding, watch this and sing along!

An ion is a charged atom – one that has gained or lost electrons in order to complete it’s outer shell and become stable.  Elements in Group 1 form ions with a charge of +1, since they lose 1 valence electron and end up with one more proton than electron.  Elements in Group 7 form ions with a charge of -1, since they gain 1 valence electron and end up with one more electron than proton.  The bond that is formed when a metal and a non-metal react in this way is called an ionic bond.  In an ionic bond, electrons are donated or received.

Covalent bonds form between non-metal elements.  This could be between the same non-metals (eg. O2) or different non-metals (eg. CO2).  In a covalent bond electrons are shared between the elements to complete the outer shells.  We use Lewis structures to represent this.  Click here for instructions on how to draw Lewis structures (also known as “dot and cross” diagrams).

To practice drawing these diagrams, here are some useful links:-

This site allows you to build your own molecules with single, double and triple covalent bonds.  If you don’t do any others, DO THIS ONE.

This one wold be good for review at the end of the topic.  It generates some multiple choice questions for you to practice identifying the correct Lewis structure.

Finally, this site allows you to construct Lewis diagrams.  It is quite advanced, but some of you might enjoy the challenge 🙂

Atomic structure

Tuesday, January 25th, 2011

Sodium2 by Mrs. Pugliano on flickr

We’ll kick off our new unit on STRUCTURES by looking at the structure of the the atom.  YOU KNOW THIS STUFF ALREADY so the first part will be a recap, then we’ll go beyond the material you covered in Grade 8.

Here’s the presentation we will use in class: KS4 The atom

And here are some practice worksheets to see if you have understood the concepts.  DO THEM! struc of atoms1   basic at struc

This is a useful resource to help you get up to speed with these ideas.

More resources: A Few Definitions   Atomic Structure Projections

Elements_compounds_or_mixtures

It’s testing time!

Friday, September 25th, 2009

You’ve all been asking, pleading, begging for another assessment.  Well, the good news is, you have one coming up next week – YEAH! 

Block H students will take it on THURSDAY 1st OCTOBER. 

Block D students will take it on FRIDAY 2nd OCTOBER.

Look through your notes from class, and go back through all the blog posts on atomic structure, the Periodic Table, electron configuration, metals vs non-metals, ionic and covalent bonding, Lewis structures, writing formulae, balancing equations et al.

COME AND SEE ME DURING TUTORIALS if you need help.

Ionic vs covalent properties

Wednesday, September 23rd, 2009

We will be doing a lab comparing the properties of ionic and covalent compounds, and trying to answer this question:

How are the properties of substances explained by theories of structure and bonding?

Read the instruction sheet for full details: LAB – How are the properties of substances explained by theories of bonding and structure

Lewis structures

Thursday, September 10th, 2009
dot and cross diagram wikimedia commons

dot and cross diagram wikimedia commons

Lewis structures, also known as dot and cross diagrams, represent the arrangement of valence electrons in elements and compounds.  This site has a detailed explanation of how to draw them.

These sites are ones we will use in class to practice.  Feel free to practice at home too 🙂

http://chemsite.lsrhs.net/bonding/flashLewis.html

http://itl.chem.ufl.edu/2045/lectures/lewis_ramyess/pjb_ramyess.html

http://education.jlab.org/elementmath/index.html

http://education.jlab.org/indexpages/teachers.php

http://www.stolaf.edu/depts/chemistry/courses/toolkits/121/js/lewis/

New Glogster homework!

Thursday, September 10th, 2009
Hydrogen from wikimedia commons

Hydrogen from wikimedia commons

Hooray!  You did such a good job on the first glogster assignment, your teachers have decided to give you another one.

Each student will be given ONE element from the periodic table.  Your task is to produce a glogster poster with information about that element.  The kinds of things to include are:

atomic structure, mass number, uses, reactivity, state, colour, etc

Remember to include pictures and images as well as text.

We will put up your posters in the shape of the periodic table outside room 1090/1091.  We’ll use the same rubric as last time to assess this.

Periodic Table

Friday, September 4th, 2009
PeriodicTable from wisegorilla.com

PeriodicTable from wisegorilla.com

We have, and will continue, to look at the Periodic Table.  Make sure you bring the paper version you were given in class with you to every lesson.  It is an important document.

Here are some resources that may be useful.  Read through the notes, and say thanks to Mr. Boulton for producing them, (with a little help from wikipedia). Classification of Elements   Comparison of groups in the periodic table

Here is the link to the video demonstrating what happens when you mix the more reactive alkali metals with water.  We will do Li and Na in class, but nothing quite as exciting as this!

Have a great no homework weekend 🙂

Atomic structure

Wednesday, September 2nd, 2009

http://science.nayland.school.nz/SimonPa/Webpage/Year11/Atomic_structure_image/atom%20structure.jpg

YOU KNOW THIS STUFF ALREADY!  You covered it in grade 8.  This is just a recap.  Click on the link to see the slides we will use in class. Atomic Structure Projections

Also, take a look at this link from the BBC Bitesize site.  It will give you some good pre-reading on the topic and help you get up to speed.