End of term exams are looming. We revised the atomic structure aspects of this topic in class today and you may choose how you do your exam revision homework.
1) Print the practise test paper out at home and answer the questions on the printout
2) Download the practise paper onto your computer and answer the questions separately on your own paper.
3) Flick through the practise paper questions on the blog and answer them on your own paper.
The reaction between sodium and chlorine to produce sodium ions and chloride ions. Atoms gain lose or share electrons to end up with a full outer shell. Compounds containing ions are called ionic compounds.
In the beginning the universe was full of hydrogen atoms.
The sun uses a series of nuclear reactions called the hydrogen cycle. In the heart of the sun protons fuse together to give a Helium nucleus. The first reaction in this sequence is very slow and explains why the sun is still shining after 5 billion years.
Homework: Put a heading in your book with the date.
The universe started off with only one element, hydrogen. Our sun burns the protons from hydrogen atoms and converts them to helium. Do a bit of research to find out how the remaining elements in the periodic table are formed. (hint: think about supernova) Write a brief account outlining how other elements are generated. The best three answers win a Mars bar.
When we started this topic the big question was ” what happens when atoms react”? We know enough now to answer this. Here is a review of the main points so far.
Elements with same number of outer electrons are arranged in columns on the Periodic Table called groups. Elements with the same number of electrons in their outer shell tend to have similar physical and chemical properties.
Finally atoms gain lose or share electrons to achieve a full outer shell like the inert gases.Now lets have a look at what happens when sodium and chlorine atoms react.
Sodium burns fiercely in an atmosphere of chlorine.
The product is a white solid, sodium chloride or ordinary table salt.
This compound is harmless.What has happened to the sodium and chlorine atoms?
Sodium burns fiercely in an atmosphere of chlorine.
The product is a white solid, sodium chloride or ordinary table salt.
This compound is harmless.
What has happened to the sodium and chlorine atoms?
Can you spot the deliberate mistake in the diagram?
The sodium atom has lost an electron to become a positively charged ion.
The chlorine atom has gained an electron to become a negatively charged chloride ion.
