We need chemistry. Example - take a gas. Suppose you want to model this gas. A fundamental approach with physics would look at the gas as a whole bunch of particles. Each particle can have an electromagnetic interaction with other particles. Great, but if you have 1 mole of this stuff, that is not very easy to model.
It's impossible. Even for a computer. The chemist would say: "it's not impossible. We used to bulls-eye wamprats back home and they are not much bigger than 2 meters. Or take some complicated molecule. How would you find the vibrational energy levels of this? You could start with shrodinger's equation and solve this quantum mechanically, but good luck. Really, if it is not hydrogen, you can't do much without some tricks. So the chemistry way allows use to make up some non-fundamental stuff and use it in a useful way.
One day, there will be no difference between chemistry and physics. As computers become more powerful but before they take over the world , maybe we will be able to model larger things with fundamental principles. Explanation: And both are needed to understand the world and universe better, along with biology and mathematics. Those are some examples in which I think that chemistry is related to physics.
Related questions How can physics help us understand what are the basic building blocks of matter? How can physics help us understand how the universe began? How does physics relate to physical therapy? How does physics help in developing computer games? How did physics change modern technology? How do physics relate to technology? Almost all of chemistry can be explained in terms of the Periodic Table. A typical experiment that is carried out to attract students to chemistry is one that involves a colour change.
When they are mixed, a yellow precipitate of lead iodide forms. Electrons in atoms and molecules stay in quantised energy levels, so the atoms or molecules will only absorb light photons of specific energy — the energy required to take an electron from one allowed quantum state to another. That is, a specific frequency and therefore specific wavelength of white light will be absorbed because energy is directly proportional to frequency and inversely proportional to the wavelength.
The new molecule will take on the complementary colour to the wavelength of light most strongly absorbed. This phenomenon of colour changing has many applications: testing solutions for their acidity or alkalinity usually involves a colour change of an indicator.
The melting point of a chemical element or compound is a simple concept: it is the temperature at which the element or compound changes state from a solid to a liquid. For most substances the melting and freezing points are the same.
What determines the melting point is the strength of the forces between the atoms or molecules: the stronger the forces, the higher the melting point. The force in the lattice is electrostatic attraction between opposite charges, which is very strong.
A great deal of thermal energy is required to overcome this force and consequently sodium chloride has a high melting point. Conversely, simple covalent compounds have low melting points, because the only forces are intermolecular forces Van der Waals forces , which are weak and thus easily broken. For most substances, the melting point and the freezing points are the same. This property of melting easily but being very stable at relatively high temperatures makes agar extremely useful as a solidifying agent.
With agar, as with all other compounds and elements, the exact point of freezing and melting is determined by the ease or difficulty with which the polymer can be broken and reassembled. This in turn is determined by the energy needed for the process to begin the activation energy which is thermodynamics, a major principle of physics. So, for agar, as for all other substances, it is the physics that explains the melting and freezing points.
Carbon is one of the basic elements of life and of all chemistry. Organic chemistry would be nowhere without it. Yet, as an element, carbon exists in two very different forms: diamond and graphite. Diamond is extremely hard, transparent, shiny, is insulating, and is a precious material; graphite is soft, opaque, conducts electricity, and is so far from precious as to be used in pencils. Here physics steps in once more to explain the difference, which is due to the arrangement of the atoms.
In diamond, each carbon atom is strongly bonded to four others in a tetrahedral arrangement. The four valence electrons of each carbon atom create very strong covalent bonds, of the same strength in all four directions, which is why diamond is so hard.
There are no free electrons, so diamond is an insulator. The very high refractive index gives diamond its treasured brilliance. Graphite is arranged quite differently. Here, the carbon atoms are arranged in layers.
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