When an atom absorbs light or when an atom bonds an electron can be gained or lost and what is left is an ion. If the ion gains an electron it has become a negative ion and if it losses an ion it becomes a positive ion. This is because the balance of the electrons protons is disturbed.
Nature is no stranger to science and within the great outdoors in area which mountainous fresh countryside areas are. It has statically been proven that these areas which make u feel comfortable and relaxed contain a high concentration of negative ions. Where as areas with high concentrations of positive ions seem to make us feel uncomfortable and irritable. After a storm the air feels clean and refreshed this because they are filled with negative ions.
Many people find the atmosphere before a storm is heavy and oppressive. This is due to the build up of positive ions within the air. Within areas high with a high concentration of positive ions it has be known to trigger of allergies and asthma.
It is all very well knowing what ions are and how they create an affect on us but how can they be recognised. The most obvious and fairly accurate way at the present time is qualitative analysis. Qualitative analysis is a body of features used to identify or quantify the chemical composition of a chemical substance. When seeking to identify a chemical in a substance scientist carry out a qualitative analysis experiment. On the other hand if a scientist wishes to find out the amount of a chemical in a substance the scientist will carry out a quantitative experiment.
We are going to carry out a qualitative analysis on our chemicals by flame testing. This process will be carried out by burning an ionic substance into a combustion flame. The results will be recorded by the visual aid of the flame changing colour the test will be carried out on seven unidentified materials.
By carrying out the flame test I hope to acquire the skill of flame testing and how to recognised cat ions and anions I also aim to carry this experiment out with a high level of accuracy.
There are many safety issues that arise when dealing with chemicals and laboratory’s that is why when conducting an experiment all safety aspects need to be thought about before carrying out the experiment otherwise someone could occur contamination or a serious injury when conducting the experiment. One of the main parts of the human body when carrying out chemical experiments are they eyes do to the fact they can easily be damaged and are clearly one of the most delicate exposed parts of the human body. To protect these fragile biological sensors a form of protection is crucial. The most common form of eye protection in the laboratory are the goggles.
The goggles appear to be very unattractive to many people but and are often interoperated as a burden and not a safety precaution. The goggles are made out of thick plastic which prevents any liquids entering the eye and causing any harm. Many people who wear contact lenses are under the illusion that there contact lenses will perform as eye protection not realising that the contact lenses are creating a risk of chemicals to become trapped between the lenses and they eye and create extensive eye damage. The goggles can also protect the eye from objects being hurled across the laboratory by immature minds or by the smashing of glass which would send pieces flying in all directions. In the case that somebody’s eye/eyes came in to contact with chemicals follow through the procedures of emergency eye was immediately:
* Water/eye solutions should not be directly aimed onto the eyeball, but rather, aimed at the base of the nose. This increases the chance of effectively rinsing the eyes free of chemicals (harsh streams of water may drive particles further into the eyes).
* Eyelids may have to be forcibly opened to attempt eye rinse.
* Flood eyes and eyelids with water/eye solution for a minimum of 15 minutes.
Clothing is also another aspect of laboratory safety it may not seem like it but It plays a vital part in protecting the skin from the harm of chemicals that is why it is advisory to cover as much of the body as possible while dealing with chemicals due to the fact that chemical can be corrosive and cause damage to the skin. The clothing can help by absorbing as much o the chemical as possible leaving hopefully a minor amount of the chemical to react with the skin. Another way of avoiding contact of chemicals with skin is to use instruments in laboratory such as pipits to transfer chemicals and tongues to handle test tubes etc.
Another aspect of safety to consider when dealing with chemicals is diffusion it is a known fact the by inhaling certain chemicals, these chemicals are labelled as toxic chemicals, can cause serious damage with in your body just by inhaling the vapour through the air. One way of preventing this is by closing lids on all chemicals after use by closing the lid you are also preventing spillages so if the container is dropped the chemical remains inside the container.
Within the laboratory there are frequent spillages that’s why it is important to try and prevent spillages and knowing what the effect of a spillage is and what to do about it. When these spillages occur they can be on minor scale or a disastrous scale. This depends whether the chemical is hazardous or not most lab spillages are on a minor scale and can simply be wiped up by using a damp cloth. With hazardous spillages do not attempt the spillage seek someone qualified to attend to the spillage.
A Bunsen burner is very common within a laboratory the importance is safety.
As u connects the Bunsen make sure that the gas pipe is secure and tight. When lighting a Bunsen burner use a splint at arms length and make sure the safety flame is on. This is done by closing the air whole located at the bottom of the Bunsen. Make sure that the Bunsen is securely placed on a heat proof mat in the centre of the table the so if the Bunsen tips over it has less of chance of inflicting injury. Before using a Bunsen burner make sure ties are tucked in, long hair is tied back, any lose items of clothing should be tightened or wrapped up and remove all unnecessary item of clothing e.g. jackets. These safety measures should be met to prevent any risk of fire. In the event of a fire take immediate safety precautions such as turning of the gas as soon as possible and call the teacher our a member of staff, if the fire is on any item of clothing you are wearing which cannot be easily removed stop drop and roll. If the fire is out of your control inform the teacher and evacuate the classroom.