Lead is a chemical element with the symbol Pb and atomic number 82. It is a heavy metal, denser than most common materials. Lead is soft and malleable, has a low melting point; when freshly cut, lead is silvery with a hint of blue. Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is a unreactive post-transition metal, its weak metallic character is illustrated by its amphoteric nature. Compounds of lead are found in the +2 oxidation state rather than the +4 state common with lighter members of the carbon group. Exceptions are limited to organolead compounds. Like the lighter members of the group, lead tends to bond with itself. Lead is extracted from its ores. Galena, a principal ore of lead bears silver, interest in which helped initiate widespread extraction and use of lead in ancient Rome. Lead production declined after the fall of Rome and did not reach comparable levels until the Industrial Revolution.

In 2014, the annual global production of lead was about ten million tonnes, over half of, from recycling. Lead's high density, low melting point and relative inertness to oxidation make it useful; these properties, combined with its relative abundance and low cost, resulted in its extensive use in construction, batteries and shot, solders, fusible alloys, white paints, leaded gasoline, radiation shielding. In the late 19th century, lead's toxicity was recognized, its use has since been phased out of many applications. However, many countries still allow the sale of products that expose humans to lead, including some types of paints and bullets. Lead is a neurotoxin that accumulates in soft bones. A lead atom has 82 electrons, arranged in an electron configuration of 4f145d106s26p2; the sum of lead's first and second ionization energies—the total energy required to remove the two 6p electrons—is close to that of tin, lead's upper neighbor in the carbon group. This is unusual; the similarity of ionization energies is caused by the lanthanide contraction—the decrease in element radii from lanthanum to lutetium, the small radii of the elements from hafnium onwards.

This is due to poor shielding of the nucleus by the lanthanide 4f electrons. The sum of the first four ionization energies of lead exceeds that of tin, contrary to what periodic trends would predict. Relativistic effects, which become significant in heavier atoms, contribute to this behavior. One such effect is the inert pair effect: the 6s electrons of lead become reluctant to participate in bonding, making the distance between nearest atoms in crystalline lead unusually long. Lead's lighter carbon group congeners form stable or metastable allotropes with the tetrahedrally coordinated and covalently bonded diamond cubic structure; the energy levels of their outer s- and p-orbitals are close enough to allow mixing into four hybrid sp3 orbitals. In lead, the inert pair effect increases the separation between its s- and p-orbitals, the gap cannot be overcome by the energy that would be released by extra bonds following hybridization. Rather than having a diamond cubic structure, lead forms metallic bonds in which only the p-electrons are delocalized and shared between the Pb2+ ions.

Lead has a face-centered cubic structure like the sized divalent metals calcium and strontium. Pure lead has a silvery appearance with a hint of blue, it tarnishes on contact with moist air and takes on a dull appearance, the hue of which depends on the prevailing conditions. Characteristic properties of lead include high density, malleability and high resistance to corrosion due to passivation. Lead's close-packed face-centered cubic structure and high atomic weight result in a density of 11.34 g/cm3, greater than that of common metals such as iron and zinc. This density is the origin of the idiom to go over like a lead balloon; some rarer metals are denser: tungsten and gold are both at 19.3 g/cm3, osmium—the densest metal known—has a density of 22.59 g/cm3 twice that of lead. Lead is a soft metal with a Mohs hardness of 1.5. It is somewhat ductile; the bulk modulus of lead—a measure of its ease of compressibility—is 45.8 GPa. In comparison, that of aluminium is 75.2 GPa. Lead's tensile strength, at 12–17 MPa, is low.

The melting point of lead—at 327.5 °C —is low compared to most metals. Its boiling point of 1749 °C is the lowest among the carbon group elements; the electrical resistivity of lead at 20 °C is 192 nanoohm-meters an order of magnitude higher than those of other industrial metals. Lead is a superconductor at temperatures lower than 7.19 K.

2007 in Bangladesh

2007 was a common year starting on Monday of the Gregorian calendar, the 2007th year of the Common Era and Anno Domini designations, the 7th year of the 3rd millennium, the 7th year of the 21st century, the 8th year of the 2000s decade. The year 2007 was the 36th year after the independence of Bangladesh, it was the first year of the regime of the fourth caretaker Government led by Fakhruddin Ahmed. President: Iajuddin Ahmed Chief Advisor: until 11 January: Iajuddin Ahmed 11 January-12 January: Fazlul Haque starting 6 January: Fakhruddin Ahmed Chief Justice: Syed Jillur Rahim Mudasser Husain, Md. Ruhul Amin In 2007 a series of floods impacted South Asia including Bangladesh. On 1 August, there was flooding on the Brahmaputra rivers. By 3 August, the main highway connecting Dhaka to the rest of the country was impassable, many districts were flood-affected and 500,000 people had been marooned. By 7 August an estimated 7.5 million people had fled their homes. By 8 August more than 50,000 people had diarrhoea or other waterborne diseases and more than 400,000 people were in temporary shelters.

As of 21 July, the flood impacted districts included Dhaka, Rajbari, Shariatpur, Netrakona and Tangail in Dhaka division. By 11 August, flood deaths were still occurring in Bangladesh, the number of people with flood-related diseases was increasing and about 100,000 people had caught dysentery or diarrhoea. By 13 August, the confirmed death toll in Bangladesh was 405. By 15 August, five million people were still displaced, the estimated death toll was nearly 500, all six of Bangladesh's divisions were affected. An severe tropical cyclone, named Cyclone Sidr resulted in one of the worst natural disasters in Bangladesh this year. Sidr formed in the central Bay of Bengal, strengthened to reach peak 1-minute sustained winds of 260 km/h, making it a Category-5 equivalent tropical cyclone on the Saffir-Simpson Scale; the storm made landfall in Bangladesh on November 15, 2007, causing large-scale evacuations. At least 3,447 deaths have been blamed on the storm, with some estimates reaching 15,000. Save the Children estimated the number of deaths associated with the cyclone to be between 3,100 and 10,000, while the Red Crescent Society reported on November 18 that the number of deaths could be up to 15,000.

Other aid agencies have estimated a death toll of up to 15,000. International groups pledged US$95 million to repair the damage, estimated at $1.7 billion. Coastal districts of Bangladesh faced heavy rainfall as an early impact of the cyclone. Dhaka and other parts of Bangladesh experienced gusty winds. Total damages came close to $450 million; the damage was extensive, including tin shacks flattened and schools blown away and enormous tree damages. Some local officials have described the damage as being worse than that from the 1991 cyclone; the entire cities of Patuakhali and Jhalokati District were hit hard by the storm surge of over 5 meters. About a quarter of the world heritage site Sunderbans were damaged. Researchers said mangrove forest Sunderban will take at least 40 years to recover itself from this catastrophe. Much of the capital city of Dhaka was severely affected, as electricity and water service were cut and significant damage was reported there due to winds and flooding; the local agricultural industry was devastated, as many rice crops — which have a December harvest — were lost.

At least 3,447 deaths have been reported. The hardest-hit area was Barguna, where 423 people were reported to have been killed, according to local officials. Patuakhali was hard-hit, with 385 deaths reported. Most of the deaths confirmed thus far were due to the winds, although 13 of them have been as a result of capsized boats in the Faridpur district of Bangladesh; the head of the Red Crescent in Bangladesh expected the death toll to reach as high as 15,000. Over 3,000 other fishermen were reported missing on over 500 fishing boats; the maximum estimated death toll from Sidr in the densely populated region is over 15,000. Note: For the year 2007 average official exchange rate for BDT was 68.87 per US$. January 11 - President Iajuddin Ahmed declares a state of emergency. January 12 - Fakhruddin Ahmed takes oath as the Chief Adviser of the caretaker government. February 22 - Muhammad Yunus, a noble prize winner, announces the formation of a new political party. March 7 - Tareq Rahman, older son of Zia and Senior Joint Secretary-General of BNP is arrested on corruption charges.

March 30 - Leaders of terrorist group JMJB are executed. April 16 - Arafat Rahman Coco, younger son of Zia is arrested on charge of money laundering. May 03: Nobel laureate Prof Muhammad Yunus backs down from forming a political party. June 11: Monsoon rain causes mudslide in Chittagong killing at least 128 people. June 30: Former President H M Ershad quits the post of Chairman of Jatiya Party. July 15: Bangladesh police detains former Prime Minister Sheikh Hasina on corruption charges. July 23: Biman Bangladesh Airlines turns into a Public Limited Company. July 30: Dhaka High Court suspends the extortion trial of Sheikh Hasina under emergency rule. August 07: Bangabandhu murder case hearing resumes after 6 years. August 20: Bangladesh seeks emergency flood aid. August 21: Five thousand Dhaka University students riot, resulting in major disruption to the university with 150 students being injured. August 22: Bangladesh imposes curfew in six cities. August 23: Bangladesh suspends indefinite curfew fo

Faisalabad International Airport

Faisalabad International Airport is an international airport and standby Pakistan Air Force military base situated on Jhang Road, 10 kilometres southwest of the city centre of Faisalabad, in the Punjab province of Pakistan. The airport is home to two flying schools who use the airfield for regular training for new cadets and aviation enthusiasts; the airport serves the population of Faisalabad and several local cities such as Tandlianwala, Jaranwala, Chiniot, Dijkot, Khurrianwala, Sangla Hill, Toba Tek Singh, Chenab Nagar, Bhawana, Pir Mahal, Chak Jhumra, Jahangir Klan, Lalian. With a large diaspora of Faisalabadis living abroad, the Pakistan Civil Aviation Authority has signed a new open policy to allow more airlines to operate from the city; the airport underwent a major transformation where the terminal building was remodelled to handle larger aircraft and passenger loads. The new terminal was opened in early 2018; the airport traces its origins to the British Raj. The city government decided that the Faisalabad had a strategic position within the South Asia and the British Empire.

In 1942, the local government gave permission for the construction of a bricked strip measuring 5000' by 100'. Regional aircraft used the strip, it played a role in the fighting and evacuation during the struggle for independence, it was known as Lyallpur Airfield and had been known as such until 1979 when the city was renamed as Faisalabad, in honour of late King Faisal of Saudi Arabia. It was henceforth renamed to Faisalabad Airport; the national flag carrier, Pakistan International Airlines began domestic operations in 1958 operating several flights from Karachi. The majority of the flights contained cargo for export. In 1965, the bricked airstrip was re-built to meet standards at that time; the surface was built using bitumen and the length of the runway increased to 9000' by 100' to allow the airport to handle larger aircraft. During 1966–1967 construction began for a terminal and apron to handle propeller aircraft such as the Fokker F-27 Friendship. In 1972 a new parallel runway with dimensions 9000 feet by 100 feet was constructed west of the existing runway, since the existing runway had deteriorated quite significantly.

The new runway was designed to handle jet fuelled aircraft such as the Boeing 737. In 1974 a jet apron, Taxiway-B, Air Traffic Control tower and Met office were constructed. A premium lounge and Instrument Landing System were installed in 1985. In 1986 the terminal building was extended to accommodate greater number of passengers. In 1991, the old runway was widened and extended reaching dimensions of 9270' by 150' with surface bitumen to accommodate Airbus aircraft such as Airbus 310s. In 1993, a business class CIP Lounge was constructed and the terminal building was extended. In 1998, direct Hajj operations were started from the airport to Saudi Arabia. On 20 December 2003, Aero Asia International launched twice a week operations from LYP to Dubai and increased its Karachi flights to thrice a week. In 2005, PIA launched direct flights from the capital city of Scotland, Glasgow to LYP with Airbus A310 aircraft; the airline launched e-ticketing from the airport in December of the same year. In December 2007, PIA operated its first Hajj flight from the city.

In 2008, PIA began to operate flights from LYP to Sialkot Airport but this was soon axed however flights to Dubai were added. In 2009, PIA launched services from LYP to Rahim Yar Abu Dhabi. In 2010, PIA connected Bahawalpur to the city. In 2011, Shaheen Air was given approval to operate seasonal Hajj flights from Faisalabad to Jeddah. In the same year, Etihad Airways launched coach services for passengers based in Faisalabad to Lahore Airport. In 2012, Shaheen Air upgraded its Hajj flights to Boeing 767s. In June 2013, PIA ended its services to Abu Dhabi and Multan due to non-availability of aircraft. Shaheen Air decided to launch operations in October of the same year to Dubai. In 2014, Air Indus launched its services to Karachi using Boeing 737-300s. On 22 February 2015, Shujaat Azeem, aviation advisor to the Prime Minister, announced on his Twitter page that LYP would be upgraded to international standards and more international flights would soon be launched from the city. On 5 March 2015 Qatar Airways announced its thrice a week service linking Doha to Faisalabad.

The service would be operated by Airbus A321/A320 aircraft. On 9 April 2015, the airport was inspected by Shujaat Azeem, Air Marshal Muhammad Yousaf, Engineer Rizwan Ashraf and Rana Mohammad Afzal Khan, it was announced that the airport will be upgraded to meet international standards of the IATA/ICAO. It was disclosed by the PCAA that the airport will undergo the following work: Extension of the current passenger terminal Construction of a new cargo complex Extension & upgrading of the current runway to handle larger aircraft Construction of a new taxiway. Renovation of the aircraft stands Renovation of the arrivals/departure/business class lounges. Renovation of the airport approach road On 1 June 2015 Air Arabia announced that it will operate thrice a week service from Sharjah and Faisalabad from 18 September 2015. Faisalabad will become the eighth city. On 15 June 2015, Flydubai announced daily flights to Faisalabad from 10 July 2015 with an increase to nine a week from 3 August. On 11 July 2015, Gerry's dnata and Royal Airport Services set up their ground handling services from the airport.

On 20 August 2015, Shaheen A