Microscopes were invented in the 1600s. Robert Hooke first looked at a thin slice of cork in 1665; he saw "a lot of little boxes." These little boxes first reminded of the little rooms monks lived in‚ so he called them cells. Hooke observed the same pattern in the stems and roots of carrots and other plants. What Hooke still did not know‚ however‚ was that cells are the basic units of living things. Ten years later‚ the Dutch scientist Anton van Leeuwenhoek focused a microscope on what seemed to
Free Atom Chemical bond Cell
Making a Potato Powered Light Bulb Materials: A large potato Two pennies Two zinc-plated nails or screws Three pieces of copper wire A very small light bulb or LED light 1) Get a potato and cut it in half. Then make a small slit in each half just big enough to put a penny into. 2) Cut two pieces of copper wire and wrap one around one of the pennies a few times‚ and wrap the other one around the other penny a few times as well. 3) Take a third piece of copper
Premium Battery Zinc Electrochemistry
about 88–92% hydrogen and 8–12% helium by percent volume or fraction of gas molecules. Since a helium atom has about four times as much mass as a hydrogen atom‚ the composition changes when described as the proportion of mass contributed by different atoms. Thus the atmosphere is approximately 75% hydrogen and 24% helium by mass‚ with the remaining one percent of the mass consisting of other elements. The interior contains denser materials such that the distribution is roughly 71% hydrogen‚ 24% helium
Premium Hydrogen Planet Jupiter
the doped fullerene with glycine molecules to design novel material for organic solar cell. Therefore‚ it would be possible to novel bio-medical applications by interacting with amino acids. This fact makes them possible to used as drug delivery vehicles for medicinal
Premium Chemistry Oxygen Spectroscopy
Another redox colour change takes place when potassium iodide‚ which is colourless‚ is oxidised by an oxidising agent to form brown iodine solution. An example of this reaction is potassium iodide solution reacting with a solution of hydrogen
Premium Oxygen Chlorine Hydrogen
Formation of hydrogen molecule (H2) Formation of Hydrogen. Atomic Number of H = 1 Electronic configuration of H = 1 Valence electron of H = 1 Hydrogen forms duet‚ to obtain stable configuration. This configuration is similar to helium (a noble gas). Since‚ hydrogen has one electron in its valence shell‚ so it requires one more electron to form a duet. So‚ in the formation of hydrogen molecule; one electron from each of the hydrogen atoms is shared. Formation of hydrogen chloride (HCl):
Free Atom Chemical bond Hydrogen
Describe how hydrogen bonding occurs between water molecules‚ and relate this and other properties of water‚ to the roles of water in living organisms. Water is a very small molecule‚ consisting of two hydrogen atoms covalently bonded to an oxygen atom. However the electrons shared are not done so equally‚ oxygen is more electronegative and has a firmer hold on the electrons and pulls them slightly towards its nucleus. Due to this‚ the charge across the molecule of water is not equally distributed
Premium Water Atom Oxygen
Chemistry •Matter • • • States Properties Classification Chemistry is the study of the composition‚ properties and structure of matter. it is considered “the central science”; blending at one extreme into physics‚ mathematics‚ engineering and sometimes into earth and life Chemistry Is the study of the matter‚ its classification‚ composition‚ properties and structure; the changes it undergoes‚ the energy transformation that goes with the change‚ and the laws and principles governing such changes
Premium Energy Chemical substance Chemistry
celestial body that has never quite become a star. A typical brown dwarf has a mass that is 8 percent or less than that of the Sun. The mass of a brown dwarf is too small to generate the internal temperatures capable of igniting the nuclear burning of hydrogen to release energy and light. A brown dwarf contracts at a steady rate‚ and after it has contracted as much as possible‚ a process that takes about 1 million years‚ it begins to cool off. Its emission of light diminishes with the decrease in its
Premium Star Sun Hydrogen
bond. The make up of nylon consists of carbon-oxygen bonds‚ carbon-hydrogen bonds‚ and nitrogen-hydrogen bonds. For example‚ 3300 cm-1‚ 29580cm-1‚ and 2800
Premium Oxygen Atom Chemistry