Transmission electron microscopy

how the elements bond together. To draw a lewis structure, first determine the number of valence electrons. Valence electrons are the number of electrons in an element’s outer most shell. After finding the number of valence electrons, you are…

He also proposed that atoms contain a cloud of electrons that orbit around the nucleus, and that most of the atom is empty space. During his time he was the scientist that knew the most and had most greatly contributed (with experiments) to the atomic theory of that time. Contribution to the modern atomic theory the modern atomic theory states that most of an atom is empty space, an atom consists of a small, dense nucleus surrounded by electrons, atoms contain subatomic particles, and the…

“No,” he answers. “They use them. Force them to build weapons and other junk…” He pauses, stepping around me. “What’re you doing? The power core’s blown.” “It’s not,” I whisper, eyes never leaving the weapon. “What?” I snap the tiny casing back on with a pop. “Said it’s not. It’s old and a bit slow, still works though. All it needed was a few wires switched and the core lineament adjusted.” I flip the switch on and the laser gun lights up, a soft purring tingling my palm. I aim at the wall and…

atom. Thanks to the evolution of atomic models. In the beginning, Democritus viewed the atom as a tiny, solid, round sphere, that was unable to be cut. He created the first model of an atom, that essentially depicted it as a solid sphere, free of electrons, protons, or neutrons that looks similar to a billiard ball. Next came Dalton, he believed that every element has its own specific atom. He also shared the belief that atoms could not be spilt,…

“Steel plates are commonly attached to each other with rivets, which are slipped into holes in the plates and rounded over with hammers. The hotness of the rivets makes them easier to round over, but their hotness has another important advantage in providing a tight fit. What is it? Explain why.” This relates to one of the characteristics of heat, in that heated objects expand, then contract when the temperature decreases, since the molecules move faster in heat and slow in the cold. The hot…

X-Rays Development of the X-Ray In 1895, a mechanical engineer and physicist named Wilhelm Roentgen created the X-ray. He was born on March 27, 1845 in Germany. So in 1895, Roentgen was playing around with a cathode ray tube and evacuated all the air inside of it and replaced it with another special gas. Then, he covered the tube so nothing escapes it, passed a current through it, and then the tube produced a fluorescent glow. After further investigations, Roentgen wanted to see how strong this…

Stereochemistry (Reaction of Haloalkanes) Stereoisomers are compounds having the same molecular formula but they are different in the special arrangement. Stereoisomers fall into two main categories Geometric isomers- This is further subdivided into cis and trans isomers. Optical Isomers In this section, we will discuss the optical isomers and how their involvement in the reactions of haloalkanes. Optical Isomers Optical isomers are compounds having the same molecular formula but they differ in…

This essay going to be about an atom. Atom is always around us all the time and ever object are made out of an atom. We, humans, are also made of the atom. Knowing about the structure and what it really is a very important thing to learn as a student. In order to learn about an atom, we will have to understand about Democritus first. So who is Democritus? Democritus is the first human to ever come up with the first atomic theory. Democritus was born in Greece around 460BC. He has a life spend…

ii. Non-Acidic Oxygen Compounds Figure 3.4 Isomers of non-acidic oxygen compounds (Retrieved from Chemistry of Petrochemical Processes, 2nd Edition, 2001). C .Asphlathenes It is organometallic compounds and inorganic salts (metallic compounds). Mostly sodium, calcium, magnesium, aluminium, iron, vanadium, nickel are present either as inorganic salts, such as sodium and magnesium chlorides, or in the form of organometallic compounds, such as those of nickel and vanadium (as in porphyrins).…

Silicon carbide has been recognised as an important structural ceramic material because of its unique combination of properties. It is a promising ceramic material that can replace conventional metals and ionic-bonded oxide ceramics such as alumina. Structure of Silicon carbide Silicon carbide is a compound of silicon, a metalloid, and carbon, a nonmetal, and has a giant molecular lattice structure. It has a similar structure with diamond. Each carbon atom is joined tetrahedrally to four…