Atomic structure:
The atomic structure of all things involved in this process is very important. It allows us to understand how all things are connected and can bond together to complete the process.
An atom consists of a nucleus which is located in the middle of the atom, this includes positive and neutral particles called protons (positive) and neutrons (neutral). Surrounding this there are shells which contain electrons (negative particles). The amount of all these things in an atom depends on which atom it is, as it differs for each element. Both the proton and neutron have a mass of roughly 1 amu (atomic mass unit), while an electron has a relative mass of 0.
A single water molecule consists of one oxygen atom and two hydrogen atoms. One single oxygen atom consists of 8 protons and 8 neutrons. It is surrounded by two shells. The first one containing two electrons and the other one 6. The first one can only hold two as that is the rule. After that the next few shells can hold up to 8 electrons. Hydrogen, on the other hand only has one proton in its nucleus, and one shell containing one electron.
oxygen atom
hydrogen atom
http://www.barrygraygillingham.com/Tutoring/AtStr.html https://www.istockphoto.com/nl/foto/atomic-structure-of-oxygen-gm183593388-27030332
When atoms are formed, their goal is to have complete outer shells. This is called the octet rule, as for most atoms, filling the most outer shel (and therefore satisfying the octet rule) means they need 8 electrons there. However, as hydrogen only has one shell, it only wants one more electron to satisfy the rule.
Bonding:
There are 3 different types of bonding. Covalent bonding, ionic bonding and metallic bonding. Each type is designed to allow all atoms involved to satisfy the octet rule. The bonding used in this specific example is covalent bonding. This type of bonding is when two or more atoms share electrons to both complete their outer shell, and form a molecule.
Water consists of one oxygen and two hydrogen atoms, as stated previously. By looking on the image, you can see that the dots represent the electrons belonging to the oxygen and the “x” represent the electrons for the hydrogen atoms. In this molecule all atoms share electrons (except both hydrogen atoms) and therefore, all satisfy the octet rule.
Butter however doesn’t have one molecular formula, rather, it is “a mixture of triglycerides.” (Reyes, 2013). Triglycerides are molecules made up of 3 fatty acids. In butter specifically, oleic acid, myristic acid, palmitic acid and searic acid make it up. The image on the right shows what its structure looks like and proves it doesn’t have the same type of bonding that we normally see in molecules, but at the same time shows that it is still a bonded structure.
Bonding is quite important as it allows for atoms to stay
together and therefore form the substances involved in this question. When we understand how the substances involved are formed and stay together, we can understand why they won’t mix and answer our question.
Periodic table:
The periodic table is a chemical table used very often to help explain things. It is a table which consists of all the chemical elements, specifically sorted into a detailed arrangement to make everything easier to understand.
The periodic table is divided up into 9 groups. (from left to right on the image, separated by colour) Alkali metals, alkaline earth metals, transition metals, post transition metals, metalloids, other non metals and noble gases. At the bottom there are lanthanoids and actinoids. These groups are groups that usually react similarly when reacting in a chemical reaction.
The columns and rows (called groups and periods) both represent different things too. Each group has the same number of electrons in the outer most shell and each period has the same number of outer shells. When counting this, we don’t count the transition metals. This means that group 13 is actually group three, and there on. This then also means that group 13 only has three electrons in it’s outer most shell.
http://ptable.com
http://ptable.com
Each specific element is arranged in the periodic table as shown in the image. The example on the image is lithium. It shows the chemical symbol (Li), its atomic mass (6.94), its atomic number (3) and how many electrons it has in each shell (2 in the first one and 1 in the second one). Each element in the periodic table is shown like this.
We can also use the periodic table to help answer this question as it allows us to understand other concepts which will directly link to answering this question.
Electronegativity:
Electronegativity plays an important role in explaining why you can’t simply wash butter off your hands with just water.
Electronegativity is the measure of how strong an atom can attract electrons towards itself (the nucleus).
The strongest electronegative atom is Fluorine.
This is because it only needs one more atom to complete the octet rule and only has two shells, which means that the want for the final electron is really strong
as it only needs one more. This also causes the attraction to be stronger as they’re closer to the nucleus and therefore don’t have to stretch it out over multiple shells. Francium, on the other hand is the least electronegative. This is due to the fact that it wants to get rid of one electron and has a lot of shells, making the force to the nucleus weaker. On the periodic table, there is an easy way to roughly see a pattern from least to most electronegative. Which is a diagonal line going upwards from left to right (as can be seen on the picture above).
Electronegativity can also occur within molecules, when one atom has a greater electronegativity than another. This creates net-negative and net-positive sides within the molecule which we call polarity.
These negative and positive sides within the molecule are important to understand as it allows us to explain why butter and water don’t mix.
Polarity:
https://users.humboldt.edu/rpaselk/C109.S11/C109_Notes/C109_lec24.htm
Polarity is the simple, one word answer to the question. Polarity can only occur when there is at least one electronegative atom within a molecule. A molecule, such as water has one atom that is more electronegative than the other. Therefore it creates net positive and net negative sides within the molecule (as can be seen in the image above). A group of electrons are huddled together more on one side of the molecule than on the other. In water, the electrons are huddled slightly more to the oxygen atom. This is due to its electronegativity. As can be supported by the image and description in the previous paragraph, oxygen is higher up on the imaginary diagonal line across the periodic table than hydrogen and therefore is proven to be more electronegative.
This can affect multiple things in the behaviour of the atom. Things such physical properties as well as the melting and boiling point. This also allows water specifically to do other tings such as hold itself together, which is called cohesion. An example of this can be seen when there is a little layer of water left on top of a coin when you pour some on. Another thing it gives water is high specific heat. This is when water absorbed heat, allowing surrounding temperatures to stay fairly within range.
The final important thing, to answer this question is it allows water to become is a dissolvent. This explains the answer. Water follows a simple “like dissolves like” policy. This means that water (a polar molecule) can only dissolve other polar molecules such as salt and sugar, for example. The polar sides of both molecules align and connect, to then form one and dissolve.
Butter is a non-polar molecule. This means that water alone couldn’t take butter off your hands as they simply don’t mix. This can also be seen with other substances such as oil. If you want to remove it from your hands, you would need a second help. An easy solution for this would be detergent. Detergent has a polar as well as a non-polar side, which is called amphiphilic. This allows it to connect to both molecules and therefore dissolve it off your hands.
https://socratic.org/questions/what-does-it-mean-when-we-say-that-water-is-a-polar-molecule.com
Why is honey thicker than water?
Intermolecular forces:
Intermolecular forces are forces that exist between neighbouring molecules. They hold the molecules together within a complete structure. There are a different types which all slightly differ in the way they work and how strong they are. They have the power to change the melting and boiling points of solids and liquids.
Although there are 3 different types of intermolecular forces (called hydrogen bonds, London dispersion forces and dipole-dipole), both honey and water have hydrogen bonds. This is the strongest type of intermolecular bond and only exists between a hydrogen atom and a different atom. This different atom could be oxygen, fluorine or nitrogen.
https://socratic.org/questions/what-are-some-examples-of-hydrogen-bonds
However, even though both these liquids have the same bonds, honey has a stronger measure of intermolecular forces than water. In the chemical structure of honey, the molecules are packed more closely together than in water and therefore the binding of particles are stronger in honey in honey than in water. This means the effects intermolecular forces bring are stronger.
Viscosity:
Viscosity is a liquid’s resistance to flow. The intermolecular forces between two atoms, determines its resistance and therefore how thick it appears to be/how slow it seems to flow (resistance). When the intermolecular forces in a certain molecule are stronger than in another, the substance will be more viscous/thick.
As stated previously, honey has stronger intermolecular forces than water. This is quite hard to achieve already as water has quite a high viscosity. However, the structure of honey allows the viscosity to be even higher. Honey has “three -OH groups within its structure which can also use hydrogen bonds to bond with other glycerol molecules”(RAL, 2012). This means that there are more hydrogen bonds within honey too. The shape of honey also allows the bond to stay stronger as it allows the molecules to get a bit entangled with one another and therefore stick together better.
Another way to prove this is by measuring it. We measure viscosity in N s m2-(Newtons seconds/m2). Water has a viscosity of 1.01 x 10-3 N s m2. but honey has one of 1.49 N s m2.
This proves that honey has much stronger intermolecular forces, and therefore a higher viscosity. This explains why honey is a thicker substance than water.
Why does the reaction rate increase with temperature?
collision theory:
Collision theory is a chemical theory that states that in order for a reaction to occur, molecules must collide. There are three basic rules that must be followed before two molecules can react. The first one is that the particles must collide. The second one is that the particles need to have sufficient energy, and finally they need to have the correct orientation. A chemical reaction occurs when the reactant’s bonds break and new ones form from the products. This can also be shown on a graph.
There are two graphs which show reaction rates. There are endothermic and exothermic graphs. The only difference, as you can see is that the straight line at the end is in a different position. The exothermic graph shows the line being lower, this means that the output (product’s) energy is more than the input (reactant’s) energy. An example of an exothermic reaction would be any combustion reaction. The second graph shows and endothermic reaction. This graph shows the opposite as the previous one, and therefore shows us that the input energy (reactant’s) is more than the output’s (product’s). An example fo a reaction like this would be melting ice cubes.
https://www.quora.com/How-can-I-make-a-graph-of-endothermic-reactions
Temperature, among other factors can contribute to the rate of the reaction. By increasing the temperature of the reaction, the particles involved gain more energy and move around quicker. This then allows for all of them to form their bonds more quickly and therefore for the reaction to occur faster than with a cooler temperature.
How are fireworks different colours?
Emission spectra:
There are many factors that contribute to the making of fireworks. However, the main topic that explains the different colours is emission spectra. Each element has its own emission spectra, which refers to each its unique wavelengths of energy. When an an atom gains energy (which in this case would be because of the fire), the electrons absorb that energy. “The ground state of an atom is the lowest energy state of the atom.” (Bewick, 2017). This then means that when the electrons absorb that energy, it is so overpowering they jump to a higher level. This is called an exited state and is only experienced when their potential energy is higher than the ground state. When the electrons jump back down to their ground state, they release the energy that it had gained before. This energy is released with a colour.
Within each firework there is some sort of powdered metal, packed in. All metals give off a different colour when releasing their energy (as can be seen on the image to the right). This is because of their own unique emission spectrum. We can also use this to identify elements when a reaction like this occurs. Fireworks are different colours as they are each packed with different metallic powders which all release different coloured energy after being lit.
– https://noschese180.wordpress.com/2014/12/16/day-68-analyzing-spectra/
Technological innovations:
In more recent times, we can use new technological inventions and innovations to better help us understand chemistry and matter. One of those inventions is the mass spectrometer. A mass spectrometer produces positive ions from the chemical substances that are then going to be analysed. It uses electric and magnetic fields to measure the mass of those particles.
Scientists mainly use this to analyse chemical substances as part of research or to help them understand other important things. There are many different types, but as all of them use the same magnetic/electric fields to exert their forces, they all consist of three main parts.
“1. A source in which ions are produced from the chemical substances to be analyzed. 2. An analyzer in which ions are separated according to mass.
3. A detector which produces a signal from the separated ions.” (JEOL, 2006)
The image here shows a diagram of the mass spectrometer and its main parts. As mentioned in the steps before, it clearly shows the ionisation, the electromagnet/deflection where the ions are separated and the detection part.
Technical innovations such as these have helped us come a far in how we see and understand chemical particles and substances. It has helped us with things such as, but not limited to environmental analysis, the analysis of petroleum products, trace metals and biological materials.
https://www.chemguide.co.uk/analysis/masspec/howitworks.html