LIGHTNING Lightning is a massive electrostatic discharge caused by unbalanced electric charges in the atmosphere‚ and resulting in a strike‚ from a cloud to itself‚ a cloud to a cloud or a cloud to ground‚ and accompanied by the loud sound of thunder. A typical cloud to ground lightning strike jumps a 5 km (3 mi) gap through the air.[1] A typical thunderstorm has three or more strikes per minute at its peak.[2] Lightning is usually produced by cumulonimbus clouds based 5–6 km (3-4 mi) above the
Premium Thunderstorm Lightning Storm
List of the First 20 Elements and their Physical Properties Atomic Radii (pm) of the First 20 Elements: - Atomic radii decreases when moving down a period‚ as the number of protons increases‚ which thence increases the effective nuclear charge. - Atomic radii increases when moving down a group‚ as the number of shells increases‚ which thence increases shielding. - The downward-sloping pattern on the above graph shows the decrease in atomic radii down a period‚ and the sudden jumps
Free Periodic table Atom
is from recycled material. McDonald does not use any CFC’s as a blowing foam agent. OTHER: Recycled materials are also used to make in-store trays. AIR: To keep the surrounding environment clean‚ McDonald’s restaurants in Hong Kong use electrostatic precipitators to remove airborne grease from the kitchen exhausts. In addition‚ exhaust outlets are properly located to prevent nuisance. Converting waste oil into useable energy: In collaboration with a waste oil recycling company approved
Premium Recycling
Lesson 03.01: History of the Periodic Table Explain how scientific observations led to the development of‚ and changes to‚ the periodic table. Russian chemist Dmitri Mendeleev set out to organize the 63 known elements according to their properties. Mendeleev wrote the name‚ mass‚ and chemical properties of each element on a separate card and arranged the cards by various properties‚ looking for trends and patterns. When he arranged the elements by increasing atomic mass‚ Mendeleev noticed that similar
Free Atom Chemical bond Ion
----------------------- 1869‚ Dmitri Mendeleev • Used cards to arrange the elements and created the first periodic table. Late 1890s‚ Joseph John Thompson • Discovered electrons using cathode ray test tube experiments • “Plum pudding” model of atoms (1900)– negative electrons in a positive framework 1800‚ John Dalton‚ English chemist: • Proposed the atomic patterns‚ which account for the law of conservation of mass and the law of constant composition
Premium Atom Chemistry Chemical element
Definition: field force -one exerted by object on another though no physical contact is made An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit Coulomb force is a law of physics describing the electrostatic interaction between electrically charged particles Charging by Conduction and Induction Static electricity can be detected by a gold leaf electroscope. One can make a model of an electroscope at home also (see box). An electroscope will be
Premium Electric charge
type of compound usually has higher melting points: ionic compounds or covalent compounds? What is the reason for this difference in melting points? (3 points) Ionic compounds have higher melting and boiling points than covalent compounds. The electrostatic attraction in an ionic bond is very strong hence a lot of heat energy is required to break it down‚ ionic bonds have high melting and boiling points. In covalent bonds‚ the intermolecular forces are very weak and are easily broken‚ hence lesser
Premium Ionic bond Covalent bond Chemical bond
on strings 35 cm long and suspended from one point. They form a 40 angle between them. What is charge Q? Ans: 0.107 C 5. A proton is placed in a uniform electric field. What must be the magnitude and direction of this field if the electrostatic force acting on the proton just balances its weight? The mass of a proton is 1.67 x 10-27 kg Ans: 1.02 x 10-7 N/C‚ up. 6. Find the resultant electric field strength at point P as shown below. Ans: 7.20 x 106 N/C‚ 56 q1= +5.6 C
Premium Electric charge
Lightning Perhaps the most known and powerful display of electrostatics in nature is a lightning storm. Lightning storms are inescapable from humankind’s attention. They are never invited‚ never planned and never gone unnoticed. The rage of a lightning strike will wake a person in the middle of the night. They send children rushing into parent’s bedrooms‚ crying for assurance that everything will be safe. The fury of a lightning strike is capable of interrupting midday conversations and activities
Premium Electric charge Lightning Electron
exists as simple molecules with weak intermolecular attraction/ weak van der Waal’s force. ∴ it has low b.p. (Do not accept bromine has weak covalent bond.) In Lead(II) bromide‚ the attraction between ions is strong/ ionic bond/PbBr2 has strong electrostatic attraction. ∴ it has higher a m.p. (Do NOT accept lead(II) bromide is an ionic compound/ ionic structure) 1 1 (ii) Lead is a metal/ The bonding between lead atoms in solid is metallic bond. There exists mobile/ delocalized (freely-moving)
Free Atom Electron