HYDROGEN Hydrogen is a gaseous element, symbol H, usually classed in group 1 (or Ia) of the periodic table Hydrogen melts at –259.2° C (–434.56° F) and boils at –252.77° C (–422.986° F). Hydrogen was confused with other gases until the British chemist Henry Cavendish demonstrated in 1766 that it was evolved by the action of sulfuric acid on metals and also showed at a later date that it was an independent substance that combined with oxygen to form water. The British chemist Joseph Priestley named the gas inflammable air in 1781, and the French chemist Antoine Laurent Lavoisier renamed it hydrogen Properties and Occurrence At ordinary temperatures hydrogen is a colorless, tasteless, and odorless gas, with a density of 0.089 g/liter at 0° C (32° F). It is highly flammable. Like most gaseous elements it is diatomic (its molecules contain two atoms), but it dissociates into free atoms at high temperatures.
With a density of density 0.89990 g/liter. The freezing point of neon is -248.67° C, and the boiling point of neon is -246.048° C, which is even lower than the boiling point of nitrogen (-195.8°C). When under low pressure, neon emits a bright orange-red glow if a small electric current is passed through it. The electron configuration of neon is 1s22s22p6. The chemical properties of neon include the fact that it is not reactive because it has a full outer shell, and therefore cannot gain or lose any electrons.
It dissolves in nitric or concentrated sulfuric acid but is resistant to alkalies. Mercury melts at -39C, boils at about 357C,and has a gravity of 13.5. The atomic weight of mercury is 200.59. Mercury comes in its pure form or combined with silver in small amounts. It is mostly found in the form of the sulfide.
In other word, when lone oxygen atom react with a breathable oxygen molecule to perform ozone. The figure shown that ozone is a bent molecule and the distances between O-----O are 127.2 pm (1.272 Å), and the angel is 116.78°. Moreover, electrons of ozone are paired which means its diamagnatic while O2 is paramagnetic because it contains two unpaired electrons. Ozone is strong oxidizing agent, unstable at high concentrations and varying length half-life. 2 O3 → 3 O2 Here is list of reactions with ozone: 1- With metals: Most metals could oxidized by ozone except (Au, Pt, Ir).
Copper is one of the best known elements, and studying its atomic structure aids in understanding why copper has the qualities it does: its fascinating characteristics are all predicted by its atomic structure. All atoms are made of three subatomic particles called the proton, the neutron, and the electron. The proton is positively charged while electrons are negatively charged and neutrons have no charge. Protons and neutrons are large and heavy compared to the electron: both the proton and the neutron have a relative mass of 1, while the electron has a relative mass of 1/1836. The heavy protons are held together in a tiny area in the center of the atom called the nucleus.
Chlorine combines with metals and nonmetals and organic materials to form hundreds of chlorine compounds. Chlorine is about 2.5 times as dense as air and moderately soluble in water, forming a pale yellowish green solution. Chlorine is so reactive that it never occurs free in nature. Chemical Properties Chlorine is in the halogen family, and like all the other halogen elements chlorine has a strong tendency to gain one electron and become a chloride ion. Chlorine readily reacts with metals to form chlorides, most of which are soluble in water.
Sir William Ramsey first discovered Helium on Earth by in uranium mineral clevite in the year 1895. When he heated the uranium mineral clevite, he noticed a bright yellow light in its spectrum. It looked the same as the D3 line that was found in the sun. It was concluded that this was the element helium. In 1903, Ramsey also discovered that helium is a product of the spontaneous disintegration of radioactive substances.
Two 18th-century scientists share the credit for first isolating elemental oxygen: Joseph PRIESTLEY (1733-1804), an English clergyman who was employed as a literary companion to Lord Shelburne at the time of his most significant experimental work, and Carl Wilhelm SCHEELE (1742-86), a Swedish pharmacist and chemist. It is generally believed that Scheele was the first to isolate oxygen, but that Priestley, who independently achieved the isolation of oxygen somewhat later, was the first to publicly announce his findings. The interpretation of the findings of Priestley and the resultant clarification of the nature of oxygen as an element was accomplished by the French scientist Antoine-Laurent LAVOISIER (1743-94). Lavoisier's experimental work, which extended and improved upon Priestley's experiments, was principally responsible for the understanding of COMBUSTION and the establishment of the law of conservation of matter. Lavoisier gave oxygen its name, which is derived from two Greek words that mean "acid former."
The weight of each drop is determined by observing its rate of free fall through the air, and using Stokes' formula for the viscous drag on a slowly moving sphere. The charges thus measured are integral multiples of e. Electrons are emitted in radioactivity <as beta rays> and in many other decay processes. The electron itself is completely stable. Electrons contribute the bulk to ordinary matter; the volume of an atom is nearly all occupied by the cloud of elec trons surrounding the nucleus, which occupies only about 10^-13 of the atom's volume. The chemical properties of ordinary matter are determined by the electron cloud.
Sulfur has a melting point of 239.38 degrees Fahrenheit, a boiling point of 832.28 degrees Fahrenheit, and the density is 2.67 g/cm. Sulfur has sixteen electrons, protons, and neutrons. When sulfur reacts with the air it produces a gaseous dioxide. It does not react with water under normal circumstances. Sulfur reacts with halogens when it is heated.