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Lead
Lead is a chemical element with symbol Pb (from the Latin plumbum) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is silvery with a hint of blue; it tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable element and three of its isotopes each include a major decay chain of heavier elements.
Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its amphoteric nature; lead and lead oxides react with acids and bases, and it tends to form covalent bonds. Compounds of lead are usually found in the +2 oxidation state rather than the +4 state common with lighter members of the carbon group. Exceptions are mostly limited to organolead compounds. Like the lighter members of the group, lead tends to bond with itself; it can form chains and polyhedral structures.
Lead is easily extracted from its ores; prehistoric people in Western Asia knew of it. Galena, a principal ore of lead, often 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 which was from recycling. Lead’s high density, low melting point, ductility 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, plumbing, batteries, bullets and shot, weights, solders, pewters, fusible alloys, white paints, leaded gasoline, and radiation shielding.
In the late 19th century, lead’s toxicity was recognized, and 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 toxin that accumulates in soft tissues and bones, it acts as a neurotoxin damaging the nervous system and interfering with the function of biological enzymes, causing neurological disorders, such as brain damage and behavioral problems.
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Led (verb)
simple past tense and past participle of lead
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Led (adjective)
Under somebody’s control or leadership.
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Lead (noun)
A Atomic number 82, symbol Pb (from Latin plumbum).
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Lead (noun)
A plummet or mass of lead attached to a line, used in sounding depth at sea or to estimate velocity in knots.
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Lead (noun)
A thin strip of type metal, used to separate lines of type in printing.
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Lead (noun)
Vertical space in advance of a row or between rows of text. Also known as leading.
“This copy has too much lead; I prefer less space between the lines.”
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Lead (noun)
Sheets or plates of lead used as a covering for roofs.
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Lead (noun)
A roof covered with lead sheets or terne plates.
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Lead (noun)
A thin cylinder of black lead or plumbago (graphite) used in pencils.
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Lead (noun)
Bullets; ammunition.
“They pumped him full of lead.”
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Lead (noun)
The act of leading or conducting; guidance; direction, course
“to take the lead”
“to be under the lead of another”
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Lead (noun)
Precedence; advance position; also, the measure of precedence; the state of being ahead in a race; the highest score in a game in an incomplete game.
“the white horse had the lead.”
“to be in the lead”
“She lost the lead.”
“Smith managed to extend her lead over the second place to half a second.”
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Lead (noun)
An insulated metallic wire for electrical devices and equipment.
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Lead (noun)
The situation where a runner steps away from a base while waiting for the pitch to be thrown.
“The runner took his lead from first.”
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Lead (noun)
The act or right of playing first in a game or round; the card suit, or piece, so played
“your partner has the lead”
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Lead (noun)
The main role in a play or film; the lead role.
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Lead (noun)
The actor who plays the main role; lead actor.
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Lead (noun)
A channel of open water in an ice field.
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Lead (noun)
A lode.
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Lead (noun)
The course of a rope from end to end.
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Lead (noun)
A rope, leather strap, or similar device with which to lead an animal; a leash
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Lead (noun)
In a steam engine, the width of port opening which is uncovered by the valve, for the admission or release of steam, at the instant when the piston is at end of its stroke.
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Lead (noun)
Charging lead. en
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Lead (noun)
The distance of haul, as from a cutting to an embankment.
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Lead (noun)
The action of a tooth, such as a tooth of a wheel, in impelling another tooth or a pallet.
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Lead (noun)
Hypothesis that has not been pursued
“The investigation stalled when all leads turned out to be dead ends.”
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Lead (noun)
Information obtained by a detective or police officer that allows him or her to discover further details about a crime or incident.
“The police have a couple of leads they will follow to solve the case.”
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Lead (noun)
Potential opportunity for a sale or transaction, a potential customer.
“Joe is a great addition to our sales team, he has numerous leads in the paper industry.”
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Lead (noun)
Information obtained by a news reporter about an issue or subject that allows him or her to discover more details.
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Lead (noun)
The player who throws the first two rocks for a team.
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Lead (noun)
A teaser; a lead-in; the start of a newspaper column, telling who, what, when, where, why and how. (Sometimes spelled as lede for this usage to avoid ambiguity.)
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Lead (noun)
An important news story that appears on the front page of a newspaper or at the beginning of a news broadcast
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Lead (noun)
The axial distance a screw thread travels in one revolution. It is equal to the pitch times the number of starts.
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Lead (noun)
In a barbershop quartet, the person who sings the melody, usually the second tenor
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Lead (noun)
The announcement by one voice part of a theme to be repeated by the other parts.
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Lead (noun)
A mark or a short passage in one voice part, as of a canon, serving as a cue for the entrance of others.
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Lead (noun)
The excess above a right angle in the angle between two consecutive cranks, as of a compound engine, on the same shaft.
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Lead (noun)
The angle between the line joining the brushes of a continuous-current dynamo and the diameter symmetrical between the poles.
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Lead (noun)
The advance of the current phase in an alternating circuit beyond that of the electromotive force producing it.
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Lead (verb)
To cover, fill, or affect with lead
“continuous firing leads the grooves of a rifle.”
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Lead (verb)
To place leads between the lines of.
“to lead a page; leaded matter”
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Lead (verb)
To guide or conduct.
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Lead (verb)
To guide or conduct with the hand, or by means of some physical contact connection.
“a father leads a child;”
“a jockey leads a horse with a halter;”
“a dog leads a blind man”
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Lead (verb)
To guide or conduct in a certain course, or to a certain place or end, by making the way known; to show the way, especially by going with or going in advance of, to lead a pupil; to guide somebody somewhere or to bring somebody somewhere by means of instructions.
“The guide was able to lead the tourists through the jungle safely.”
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Lead (verb)
: To direct; to counsel; to instruct
“A good teacher should lead their students to the right answer.”
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Lead (verb)
To conduct or direct with authority; to have direction or charge of; to command, especially a military or business unit.
“to lead a political party”
“to lead the search team”
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Lead (verb)
To guide or conduct, as by accompanying, going before, showing, influencing, directing with authority, etc.; to have precedence or preeminence; to be first or chief; — used in most of the senses of the transitive verb.
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Lead (verb)
To begin, to be ahead.
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Lead (verb)
To guide or conduct oneself in, through, or along (a certain course); hence, to proceed in the way of; to follow the path or course of; to pass; to spend. Also, to cause (one) to proceed or follow in (a certain course).
“The evidence leads me to believe he is guilty.”
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Lead (verb)
To go or to be in advance of; to precede; hence, to be foremost or chief among.
“the big sloop led the fleet of yachts;”
“the Guards led the attack;”
“Demosthenes leads the orators of all ages”
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Lead (verb)
To lead off or out, to go first; to begin.
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Lead (verb)
To be more advanced in technology or business than others.
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Lead (verb)
To begin a game, round, or trick, with
“to lead trumps”
“He led the ace of spades.”
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Lead (verb)
To be ahead of others, e.g., in a race.
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Lead (verb)
To have the highest interim score in a game.
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Lead (verb)
To step off base and move towards the next base.
“The batter always leads off base.”
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Lead (verb)
To aim in front of a moving target, in order that the shot may hit the target as it passes.
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Lead (verb)
To draw or direct by influence, whether good or bad; to prevail on; to induce; to entice; to allure
“to lead someone to a righteous cause”
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Lead (verb)
To tend or reach in a certain direction, or to a certain place.
“the path leads to the mill;”
“gambling leads to other vices”
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Lead (verb)
To produce (with to).
“The shock led to a change in his behaviour.”
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Lead (verb)
misspelling of led
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Lead (adjective)
Foremost.
“The contestants are all tied; no one has the lead position.”
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Lead (adjective)
main, principal
“the lead guitarist”
“lead trumpet”
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Led (noun)
a light-emitting diode (a semiconductor diode which glows when a voltage is applied)
“light sources can be fluorescent tubes, optical fibres, or LEDs”
“an LED display”
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Lead (verb)
cause (a person or animal) to go with one by holding them by the hand, a halter, a rope, etc. while moving forward
“she emerged leading a bay horse”
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Lead (verb)
show (someone or something) the way to a destination by going in front of or beside them
“she stood up and led her friend to the door”
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Lead (verb)
be a route or means of access to a particular place or in a particular direction
“a farm track led off to the left”
“the door led to a long hallway”
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Lead (verb)
be a reason or motive for (someone)
“nothing that I have read about the case leads me to the conclusion that anything untoward happened”
“a fascination for art led him to start a collection of paintings”
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Lead (verb)
culminate or result in (a particular event or consequence)
“closing the plant will lead to 300 job losses”
“fashioning a policy appropriate to the situation entails understanding the forces that led up to it”
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Lead (verb)
be in charge or command of
“a military delegation was led by the Chief of Staff”
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Lead (verb)
organize and direct
“the conference included sessions led by people with personal knowledge of the area”
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Lead (verb)
be the principal player of (a group of musicians)
“since the forties he has led his own big bands”
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Lead (verb)
set (a process) in motion
“they are waiting for an expansion of world trade to lead a recovery”
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Lead (verb)
start
“the radio news led with the murder”
“Ned leads off with a general survey of the objectives”
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Lead (verb)
make an attack with (a particular punch or fist)
“Adam led with a left”
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Lead (verb)
(of a base runner) be in a position to run from a base while standing off the base.
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Lead (verb)
(in card games) play (the first card) in a trick or round of play
“he led the ace and another heart”
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Lead (verb)
have the advantage over competitors in a race or game
“he followed up with a break of 105 to lead 3-0”
“the Wantage jockey was leading the field”
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Lead (verb)
be superior to (competitors or colleagues)
“there will be specific areas or skills in which other nations lead the world”
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Lead (verb)
have or experience (a particular way of life)
“she’s led a completely sheltered life”
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Lead (noun)
the initiative in an action; an example for others to follow
“Britain is now taking the lead in environmental policies”
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Lead (noun)
a piece of information that may help in the resolution of a problem
“detectives investigating the murder are chasing new leads”
“I have a lead on a job that sounds really promising”
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Lead (noun)
someone or something that may be useful, especially a potential customer or business opportunity
“setting up a social networking page can help you get numerous leads”
“the goal of marketing is to generate leads so the sales people can close them”
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Lead (noun)
(in card games) an act or right of playing first in a trick or round of play
“it’s your lead”
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Lead (noun)
the card played first in a trick or round
“the ♦8 was an inspired lead”
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Lead (noun)
a position of advantage in a contest; first place
“the team burst into life and took the lead”
“they were beaten 5-3 after twice being in the lead”
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Lead (noun)
an amount by which a competitor is ahead of the others
“the team held a slender one-goal lead”
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Lead (noun)
the chief part in a play or film
“she had the lead in a new film”
“the lead role”
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Lead (noun)
the person playing the chief part
“he still looked like a romantic lead”
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Lead (noun)
the chief performer or instrument of a specified type
“a lead guitarist”
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Lead (noun)
the item of news given the greatest prominence in a newspaper, broadcast, etc.
“the ‘pensions revolution’ is the lead in the Times”
“the lead story on CNN”
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Lead (noun)
the opening sentence or paragraph of a news article, summarizing the most important aspects of the story
“the newswire will be offering two different leads for certain stories, so editors can pick and choose”
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Lead (noun)
a strap or cord for restraining and guiding a dog or other domestic animal
“the dog is our constant walking companion and is always kept on a lead”
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Lead (noun)
a wire that conveys electric current from a source to an appliance, or that connects two points of a circuit together.
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Lead (noun)
the distance advanced by a screw in one turn.
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Lead (noun)
an artificial watercourse leading to a mill.
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Lead (noun)
a channel of water in an ice field.
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Lead (noun)
a soft, heavy, ductile bluish-grey metal, the chemical element of atomic number 82. It has been used in roofing, plumbing, ammunition, storage batteries, radiation shields, etc., and its compounds have been used in crystal glass, as an anti-knock agent in petrol, and (formerly) in paints.
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Lead (noun)
used figuratively as a symbol of something heavy
“Joe’s feet felt like lumps of lead”
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Lead (noun)
an item or implement made of lead.
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Lead (noun)
sheets or strips of lead covering a roof.
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Lead (noun)
a piece of lead-covered roof.
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Lead (noun)
lead frames holding the glass of a lattice or stained-glass window.
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Lead (noun)
a lump of lead suspended on a line to determine the depth of water.
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Lead (noun)
graphite used as the part of a pencil that makes a mark
“scrawls done with a bit of pencil lead”
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Lead (noun)
a blank space between lines of print.